Question

If x represents the rate that Joy traveled at for the first half of the trip, write an

expression that represents the amount of time it takes Joy to complete the second half of the
trip at the slower rate.

Answer 1

time taken for trip 2nd half > time taken for trip 1st half

Explanation:

Let the total distance of Joy's trip be = D

Then, the first half distance travelled = D/2

The rate (speed) at which Joy travels during first half = x

So, time taken to travel first half = Distance / Speed

= (D/2) / x = D / 2x

• Second half of trip distance travelled = remaining D/2

Let the rate (speed) at which Joy travels during second half = x'

As given, x' (second half speed) < x (first half speed)

So, time taken to travel first half = Distance / Speed

(D/2) / x' = D / 2x'

As x' < x : D / 2x' > D / 2x .

Trip 1st half Time taken trip < 2nd half ; or trip 2nd half time taken > 1st half