Question

The length and width of a playground is 80 m and 35 m respectively.
(i) Find the cost of levelling, it at *4.50 per square meter?
(ii) How long will a boy take to go three times round the field, if he walks at the rate of 1.5m per second?
plz give me ans.​

Answer 1

Answer:

i) Rs. 12600

ii) 460 seconds

Step-by-step explanation:

length (l) = 80m

breadth (b) = 35m

• area = l * b

= 80 * 35

= 2800 sq. m

• The cost of leveling = 2800*4.5

= Rs. 12600

• perimeter =2(l + b)

= 2* (115)

= 230 m

the boy is going 3 times around the ground

• distance = 3* 230 = 690 m

• time = distance /speed

• t= 690/1.5

=460 s

• Hence, Cost of leveling the playground = Rs. 12,600

• And time required for the boy to go three times round the ground = 460 seconds

Answer 2

(i) The cost of leveling, the playground at *4.50 per square meter is Rs 12600

(ii) A boy takes 460 seconds to go three times around the field if he walks at the rate of 1.5m per second

Given:

• The length of a playground is 80m
• The breadth of the playground is 35m

To find:

(i) Find the cost of leveling, it at Rs.4.50 per square meter?

(ii) How long will a boy take to go three times around the field, if he walks at the rate of 1.5m per second?

So,

• Leveling is done in the area of the playground.

(i) The area of the playground = length * breadth units sq.

The area = 80 * 35

               =  2800 m sq

                       

The cost of leveling per m sq. = Rs 4.50

Then the cost of leveling 2800 m sq = 4.50 * 2800 = Rs. 12600

Now,

(ii) Perimeter of the playground = 2(l + b) units

= 2( 80 + 35)

= 2 * 115

= 230 m

• A boy goes three times around the field.

3 rounds = 3 * perimeter of the playground

               = 3 * 230

               = 690 m

If he walks 1.5m per second

Then the time take to complete 690 m

= 690/1.5 = 460 seconds