Question 936885
John drives from town A to town B at 90kmh for T Hours
Jenny drives the same journey at 70kmh. she travels for 1 hour longer than John

How long did John drive for.
Assume constant speeds

The distance from A to B is 90T

Jenny time = 90 T/70

Jenny's time - john's time = 1
t=d/r

90T/70 -T = 1

90T-70T =70

20T=70
T= 70/20
T= 7/2

T=3.5 hours