Question 871504
Po Ling can bicycle 75 mi in the same time it takes her to drive 165 mi. If she drives 30mph faster than she bikes, how fast does she bike ?   

Both times are same

cycle speed be x
distance = 75 miles
t= 75/x

Car speed = (x+30)
car distance = 165 miles

t= 165/(x+30)

165/(x+30)= 75/x

cross multiply
165x=75(x+30)

165x=75x+2250

165x-75x=2250
90x=2250
/90
x= 25

Cycle speed = 25 mph