Question

plss solve...
(9)the length and breath of playground are 80m and 35m respectively.
a) how long will a boy take to go three times round the field, if he walks at rate of 1.5m per second?

Answer 1

perimeter of the playground = 2(l+b)
=2*115
=230m
round 3 times=230*3
=690m
walks at rate of 1.5m/s=690/1.5
=490 seconds
=8.16 minutes

Answer 2

Given:

⇒ Length of playground = 80m.

⇒ Breadth of playground = 35m.

We know that Area of playground = length * breadth

                                                         = 80 * 35

                                                         = 2800.

We know that Perimeter of playground = 2(l + b)

                                                                  = 2(80 + 35)

                                                                  = 2(115)

                                                                  = 230.

So, Distance covered in 1 round = 230 m.

Then, 3 times round the field = 230 * 3

                                                 = 690 m.

We know that Time = Distance/Speed

⇒ 690/1.5

⇒ 460 seconds

(or)

7 min 40 seconds.

Hope this helps!