She wants all her rows in 6 so she needs a number of cars divisible by 6 which the next one would be 24 so she needs 1 additional car
Number of cups you have / number of friends to share it between = 6/8
You can simplify 6/8 by dividing both the numerator and the denominator by 2.
6/8 = 3/4 or 0.75 of a cup
