on monday, Roger drove to work in 20 minutes. on tuesday, he averaged 15 miles per hour more, and it took him 6 minutes less to get to work. how far in miles does he travel to work?

Question

anonymous · Answer

x = distance
y = velocity

x/y = 20/60
x/y+15 = 14/60

x = 11.7 miles
y = 35 mph

welshfella · Answer

first we need to convert minutes to hours as we are dealing with mph.
20 minutes = 1/3 hour and 14 minutes = 7/30 hours
v = speed , x = distance    v = s/t

we have the 2 equations

v = x / 1/3  = 3x

v + 15 = x / (7/30) = 30x/7

substitute v = 3x in 2nd equation:-

3x + 15 = 30x/7

21x + 105 = 30x
9x = 105
x = 11.7 miles

welshfella · Answer

* thats v = x/t