Question

17. Distance to Work Johnny gets to work in 20 minutes
when he drives his car. Riding his bike (by the same
route) takes him 45 minutes. His average driving speed
is 4.5 mph greater than his average speed on his bike.
How far does he travel to work?

Answer 1

Answer:

2.25 miles

Step-by-step explanation:

When driving a car time taken is 20 minutes. This is equal to 20/60 hours , 1/3 hours / 0.3 hours

When riding a bike , time taken is 45 minutes. This is 45/60 hours , 3/5 hours/ 0.75 hours

The formula for speed is : Speed = Distance covered / time taken

The statement is that the driving speed is greater than biking speed by 4.5 mph

Assuming the distance to work is x miles then;

x/ 0.3 - x/0.75 = 4.5  ------eliminate 0.3 by multiplying each term by 0.3 to get

x- 0.3/0.75 x = 1.35 -------eliminate 0.75 by multiplying each term by 0.75 to get

0.75 x - 0.3 x = 1.0125

0.45 x = 1.0125

x= 1.0125 / 0.45

x = 2.25