Ilya and Anya each can run at a speed of 7.40 \ m{mph} and walk at a speed of 3.
ID: 2042935 • Letter: I
Question
Ilya and Anya each can run at a speed of 7.40 m{mph} and walk at a speed of 3.00 m{mph}. They set off together on a route of length 5.00 m{miles}. Anya walks half of the distance and runs the other half, while Ilya walks half of the time and runs the other half.How long does it take Anya to cover the distance of 5.00 m{miles}?
Express your answer numerically, in minutes.
Find Anya's average speed.
Express Anya's average speed s_ave,Anya numerically, in miles per hour.
How long does it take Ilya to cover the distance?
Express the time t_Ilya taken by Ilya numerically, in minutes.
Now find Ilya's average speed.
Express Ilya's average speed s_ave,Ilya numerically, in miles per hour.
Explanation / Answer
a) Anya walks 2.50 mi at 3.80 mph and runs 2.50 mi at 8.90 mph
((2.50/3.80) + (2.50/8.90)) x 60 ? 56.33 min
b) Anya's avg speed = 5.00/.938 = 5.33 mph
c) Ilya walks at 3.80 mph for t/2 and runs at 8.90 for t/2.
3.80(t/2) + 8.90(t/2) = 5.00
1.9t + 4.45t = 5.00
6.35t = 5.00
t = 5.00/6.35 = 0.787 hr
t = (0.787)60 ? 47.22 min
d) IIya's avg speed = 5.00/0.787 = 6.35 mph