The ratio of the number of cars to the number of SUVs in a parking lot is 4:1. The ratio of the number SUVs to the number of Minivans is 4:5. (A) Find the ratio of the number of minivans in the parking lot. (B) if there are 20 minivans, how many vehicles are there all together?

Please help me understand thanks.

1 answer

cars : SUV's = 4:1 = 16:4
SUV's : Minivans = 4:5

now that I have a common "4" for the SUV's in both, I can say

cars : SUV's : minivans = 16 : 4 : 5
or
= 16x : 4x : 5x

but 5x = 20
x = 4

so we have 64 cars, 16 SUV's , and 20 minivans for a total of 100 vehicles

check:
cars: SUV's = 64:16 = 4 : 1
SUV's : minivans = 16 : 20 = 4 : 5
My answer is correct