To attend a family reunion, Beth drives 100 mi from Fresno and Clara drives 220 mi from San Jose. Both women drive the same speed in miles per hour, but Clara's drive takes 2 hours longer than Beth's. Find the length of Beth's drive.

Question

a. 1 hour. b. 2.2 hours
c. 1.66 hours d. 3.66 hours

Answer 1

distance = rate * time

100 = Beth rate * t
220 = Clara rate *(t+2)
BUT
we know that the two rates are the same, call it v

100 = v * t
so
v = 100/t
and

220 = v * (t+2)
or
220 = (100/t)(t+2)
220 t = 100 t + 200
2.2 t = t + 2
1.2 t = 2
t = 2/1.2 = 1 .67 hours which is 1 hour and 40 minutes

Answer 2

Thanks