Average Speed- Word Problem (Addition, Subtraction, Multiplication, Division )

Average Speed

The distance travelled in unit time by an object is called its speed.

Average speed is defined as distance travelled per unit time. 

For example, if you cycle 2.4 km in 10 minutes, then your average speed would be 

                      2400 m/ 10 x 60 s  

                        =  24/6 m/s

                         = 4 m/s

1. The distance between Mumbai and Pune is 180 km. A bus takes about 4 hours to cover the distance. What is the average speed of the bus?

Solution:

Average speed  = Distance / time

                          = 180/4 km/h

                          = 45 km/h

The most commonly used units for speed are km/h and m/s.

Speed  = Distance/Time

Distance = Speed x Time

Time = Distance covered / Speed

Average speed is defined as distance travelled per unit time. It is calculated when the distance travelled per hour is not uniform due to stoppage, slowing down etc.

2. A train travels for 3 hours at a speed of 121 km/h. How much distance does it cover in that time?

Applying the unitary method, we get:

In 1 hour, the train travels 121 km

In 3 hours, the train travels   121 x 3 = 363 km

Thus, we observe that

Distance = Speed x Time

Grade- 3 Word Problem

Addition

Q.1. For annual sports competition, Sujan runs daily 100 meters, 400 meters and 800 meters. How many meters does he run daily?

Solution:

Daily Sujan runs = ( 100 + 400 + 800) meters

 

                                  = 1300 meters

Ans: He runs 1300 meters daily.

Q.2. Limu finished reading three story books containing 261 pages, 275 pages and 350 pages in a month. How many pages did she read in that month?

Solution:

Limu finished reading there story books.

                           1st  book containing            261  pages

                           2nd   book containing          275  pages

                          3rd    book   containing        350 pages

                                                  Total          =  886 pages

           Ans: Limu finished reading 886 pages of books in that month.

Q.3. In a pond, 1200 fry of Rui, 985 fry of Katla and 765 fry of Mrigel were dropped. How many fry were dropped in that pond?

Solution:

      In a pond,

                   Rui            =  1200 fry

                   Katla         =    985 fry

                   Mrigel       =    765  fry

                   Total       =  2950 fry

         Ans: 2950 fry were dropped in that pond.

Q.4. 530, 736 and 890 mangoes were plucked from 3 mango trees of Mina's fruits garden. How many mangoes were plucked from the garden?

Solution:

Mangoes plucked from 1st mango tree  530 mangoes

                                         2nd                     736

                                         3rd                     890

                                       Total plucked = 2156 mangoes

Ans: 2156 mangoes were plucked from Mina's garden.

Q. 5. There are 620 rose, 832 China rose and 946 marigold saplings in a nursery. How many saplings are there in that nursery?

Solution:

There are   620 Rose saplings

                   832 China Rose saplings

                   

                   946 Marigold saplings

     Total  = 2398  saplings

Ans: There are 2398 saplings in the nursery.

Q.6. In the book fair, Raju sold books worth $ 1150  on the first day, $ 1225  on the second day, $ 1575  on the third day and $ 2000  on the forth day. What was the total worth of books he sold in four days?

Solution:

In the book fair,

Books sold on the 1st day  =  $ 1150 

                               2nd        = $ 1225 

                               3rd        = $ 1575 

                               4th      =   $  2000 

Books sold in 4 days for =    $ 5950 

Ans: He sold books of $ 5950  in 4 days.

 

Subtraction

Q.1. Monthly income of Nazma Begum is 8950 $ and her monthly expenditure is 8725 $. How much is her monthly savings?

Solution: 

       Nazma Begum's,

                                   Monthly income               $ 8950 

                                  Monthly expenditure       $ 8725 

                                  Monthly savings                 $ 225  

                     Ans: Her monthly savings is $ 225 .

Q.2. In a cricket game, Bangladesh scored 386 runs and Australia scored 242 runs. Which team scored more runs and how many more runs?

Solution:

    In a cricket game,

                       Bangladesh scored         386 runs

                       Australia scored              242 runs

                  Bangladesh scored more by 144 runs

       Ans: Bangladesh team scored more runs and 144 more runs.

Q.3. In the book-fair Mr. Summon sold books worth $ 3260 on the first day and worth $ 5785 on the second day. How much more money did he get on the second day.

Solution:

In the book-fair,

Sold books on the second day    $ 5785

                             

                                first               $ 3260

The second day sale is more by   $ 2525

Ans: He got $ 2525 more on the second day.

Q.4. Luna has $ 2650 and Suna has $ 1230. How many more money does Luna have?

Solution:

          Luna has          $ 2650

          Suna has           $ 1230

Luna has more by     $ 1420

Ans: Luna has  $ 1420 more than Suna.

 Q.5. In a nursery there are 988 Rose saplings and 672 China rose saplings. How many more Rose saplings are there in that nursery?

Solution:

In a nursery,

                             There are 988 Rose saplings

                                               672 China rose saplings

Rose saplings are 316 saplings more by

Ans: There are 316 more Rose saplings in that nursery.

Q.6. Mr. A. Karim went to market with $1250. He spent $ 960. How much money remained with him?

Solution:

Mr. A. Karim had    $ 1250

He spent                   $ 960

remained               $  290

Ans: $ 290 left with him.

Q.7. What number should be subtracted from 475 to get 250?

Solution:

               One number    =   475

      Other   number        =   250

To be subtracted            = 225

Ans: 225 number should be subtracted.

Q. 8. In a school, there are 1475 students. The number of girl students is 930. What is the number of boy students?

Solution:

            In school total students are 1475

              Number of girl students      930

            Number of boy students       = 545

Ans: The number of boy students 545.

Q.9. The number of population of Syedpur village is 3876. The number of males is 1943. What is the number of females?

Solution:

The total number of population is 3876

The number of males is                  1943

The number of females is              1933

Ans: The number of females is 1933.     

 Multiplication

1. If there are 6 flowers in a bundle, then how many flowers will be in 8 bundles?

Ans:  1 bundle has 6 flowers

       8 bundles have = ( 6 X 8 ) flowers

                                 = 48 flowers

Ans: There are 48 flowers in 8 bundles.

2. Toma reads books 4 hours daily. How many hours does she read in a week?

Solution:

We know that,

                1 week = 7 days

In      1 day   Toma   reads      4 hours

In     7 days   Toma   reads  =    ( 4 X 7 ) hours

                                              = 28 hours

                        Ans: Toma reads 28 hours in a week.

3. There are 24 sheets of paper in a quire. How many sheets will be in 12 quire?

Solution:

                  In    1 quire there are        24 sheets

                  In    12 quire there are   = ( 24 X 12) sheets

                      

                                                           =  288 sheets

                 Ans: There are 288 sheets in 12 quire of paper.

4. There are 15 rows of betel-nut trees in Ramu's garden and there are 24 trees in each row. How many trees are there in the garden?

Solution:

           In         1 raw there are       24 trees

          In        15  raw there are   = ( 24 X  15 )

                                                   = 360 trees

Ans: There are 360 trees in the garden.

5. Tondra Chakma drives at the rate of 45 km per hour. How many km will she go in 8 hours at the same speed?

Solution:

In     1 hour Tondra Chakma drives 45 km

In     8 hours she drives                     = (45 x 8 ) km

                                                           = 360 km

Ans: She will run 360 km in 8 hours.

6. There are 130 pages in a book. How many pages are there in 28 such books?

Solution:

1 book contains   =   130 pages

28 books contain =  (130 x 28 ) pages

                            = 3640 pages

Ans: There are 3640 pages in 28 books.

7. Nipu has 14 times of what Rimi has. If Rimi has $ 225, then how much money does Nipu have?

Solution:

                   Rimi    has     $ 225

                Nipu       has   = ($ 225 x 14 ) 

                                        = $ 3150

Ans:   Nipu has  $3150.

   Division

* The number by which division is done is the divisor.

* The number which is divided is the dividend.

* The number obtained after the division is the quotient.

* The number which remains after the division is the remainder.

* Remainder must be smaller than the divisor.

* If the remainder is zero, then the dividend is thoroughly divisible by the divisor.

1. In the class, there are 41 students. 3 students can sit in each bench. How many benches will be needed for them?

solution;

             3 students can sit in    1 bench

           41 students can sit in  = 41 / 3

                                                = 13  bench

But    1 bench is needed for remainder 2 students

They needed     = (13 + 1)        

                         = 14 benches

Ans:  14 benches will be needed for them.

2. There are 83 pencils and 7 students. How many pencils will each student get if they share the pencils equally?

Solution:

       7 students  will get 83  pencils

    1 student  will gets   = ( 83 / 7) pencils

                                     = 11 pencils

    Ans: So, each will get 11 pencils and 6 pencils will remain.

3. In a class, there are 45 students. 5 students can sit in each bench. How many benches will be needed for them to sit?

Solution:

5 students sit in   1 bench

45 students sit in   = (45 / 5) benches

                             =  9  benches

Ans: 9 benches will be needed for them to sit.

4. One year equals 365 days. How many weeks and days does 1 year have?

Solution:

We know,

                1 week    =   7 days

                  7 days   =   1 week

               365  days =  365/7

                               = 52 weeks  1 day

Ans: There are 52 weeks and 1 day in a year.

 

Average Speed 

Q.1. Priya sets off from her home on a 70 km journey to her friends' house. She travels the first 40 km of her journey at an average speed of 40 km/h and the remaining at an average speed of 60 km/h. Calculate the average speed for her entire journey.

 Solution:
   Time taken for first part of journey   =  40/40
                                                               = 1 hour
  Time taken for second part of journey  = 70 - 40 / 60
                                                                  = 30 / 60
                                                                 = 1/2 hour
                                Total time taken   = 1 + 1/2  
                                                                                                                                                              = 1 1/2  hour

    Average speed  = Total distance travelled / Total time taken

                                                  = 70/3/2
                                                   =  46   2/3 km/h

    Q.2. In a triathlon, Farhan swims a distance of 1.5 km at an average speed of 2.5 km/h, cycles 40 km in 1 1/2  hours and runs at an average speed of 9 km/h  for 1 1/9 hours. Find his average speed for the entire competition.