Question

Stanley runs, swims, and bikes every day. During these workouts, heruns at 9 mph, bikes at 16 mph, and swims at 2.5 mph. Yesterday, he ranfor half an hour longer than he swam, and his biking time was twice hisrunning time. How long did Stanley run, swim, and bike yesterday if thetotal distance he covered was 64 miles

Answer 1

Equations

Let's call:

x = time Stanley swam yesterday.

We know he ran for half an hour longer than he swam, thus the time he ran was:

x + 0.5 = time Stanley ran yesterday

We also know he biked for twice the time he ran, thus:

2(x + 0.5) = time Stanley biked yesterday.

The distance covered by Stanley when swimming is

2.5*x

The distance covered by Stanley when running is:

9*(x+0.5)

The distance covered by Stanley while biking is:

16*2*(x + 0.5) = 32(x + 0.5)

The total distance is 64 miles, thus:

2.5*x + 9*(x+0.5) + 32(x + 0.5) = 64

Operating:

2.5x + 9x + 4.5 + 32x + 16 = 64

Simplifying:

43.5x + 20.5 = 64

Subtracting 20.5:

43.5x = 43.5

Thus:

x = 1

Stanley swam for 1 hour, he ran for 1+0.5 = 1.5 hours and biked for 2*1.5=3 hours

Swam: 1 hour, Ran: 1.5 hours, Biked: 3 hours