For this case you can solve the problem by applying a simple rule of three in which we have
520 ---> 100%
800 ---> x
Clearing x we have
x = (800/520) * 100 = 154%
the percentage increase in cost was
154-100 = 54%
answer
the percentage increase in cost was 54%
The answer would be -18 and 3
the answer is a) because its the numerator is bigger than the denominator
54 miles
using the formula
speed =
=
= 12 mph
continuing at 12 mph then
distance = speed × time = 12 × 4.5 = 54 miles