Question

Q20) The length and breadth of a playground are 75.20m and
34.80m respectively.
a) Find the cost of levelling it at 1.50 per square meter.
b) How long will a boy take to go three times round the field if he
walks at the rate of 1.5m per second.​

Answer 1

Answer:

22/ 3 minutes = 7 min 20 secs

Step-by-step explanation:

Length of the play ground.= 75m 20 cm = 75.20m

Breadth of the playground = 34 m 80 cm = 34.80m

Therefore area of the playground =(75.20×34.80)m square =2616.96m per square

Perimeter of the playground = 2 (75.20+34.80)m

2(110)m = 220m

1. Cost of levelling =rs 1.50×2616.96

=rs 3/2×2616.96

= rs(3×1308.48)

2. Distance travelled to go round the field once =220m

Therefore to go round to the field 3 times= 3× 220= 660m

(660÷1.5 secs ) (t = d/s )

=(660÷15/10) sec = 660×10/15

=440 secs = 440/60 min

= 22/ 3 minutes = 7 min 20 secs

Please mark it as brainiest answer