Question

Emily drove to town with an average speed of 32 miles per hour, and then back home with an average speed of 38 miles per hour. If her total traveling time was 42 minutes, how far is it from home to town?

Answer 1

It is given that,

→ s1= 32 miles/h

→ s2 = 38 miles/h

Now t1 + t2 is,

→ 42 min

→ 42/60 hours

→ 7/10 hours

The formula we use,

→ Time = Distance/Speed

→ t = d/s

Then the total time is the,

Sum of time values to and from the town.

→ d/32 + d/38 = 7/10

→ d/16 + d/19 = 7/5

→ d{(1/16) + (1/19)} = 7/5

→ d(16 + 19) = (7/5) × (16 × 19)

→ 35d = 425.6

→ d = 425.6/35

→ d = 12.16

Hence, the distance is 12.16 miles.

Answer 2

• 12.16 miles

Explanation:

Speed - s, Distance - d, Time - t

Equation of time is:

• t = d/s

Given,

• s1 = 32 m/h, s2 = 38 m/h, t1 + t2 = 42 min = 42/60 h = 7/10 h

Total time is the sum of time values to and from the town:

• d/32 + d/38 = 7/10
• d/16 + d/19 = 7/5
• d(1/16 + 1/19) = 7/5
• d(16 + 19) = 7(16*19)/5
• 35d = 425.6
• d = 425.6/35
• d = 12.16