Question

PLEASE ANSWER FAST!!! IT'S URGENT! A boy skates across a pond with the wind and returns against the wind. The speed of boy without wind is 15 mph, and the speed of the wind is 2 mph. If he takes 40 minutes for the round trip, find the width of the pond. Also find the boy's average speed on the round trip. Express your answer as decimals to the nearest tenth.

Answer 1

t1 = S / (15 + 2) time to cross with wind

t2 = S / (15 -2) time to cross against wind

t = t1 + t2 = S / 17 + S / 13 = 30 S / 221 = .136 S where t is in hours

S = .667 hrs / .136 hrs/mi = 4.90 mi

Avg speed = 2 * 4.90 mi / .667 hr = 14.7 mph