Arithmetic Reasoning
Ratios
Yesterday I presented a question on ratios.
If there is a 6:3 ratio of cars to trucks, and there are a total of 81 vehicles, how many cars are there?
As an ASVAB tutor, I remind my students of the importance of reviewing ratios for the Arithmetic Reasoning section of the ASVAB. Ratios are closely related to proportions. Many ratio problems can be solved as proportions while some are not.
This example is not solved as a proportion.
It tells us that there is a 6:3 ratio of cars to trucks.
This means that there are 6 cars for every 3 trucks.
Then the question tells us that the total number of vehicles in 81.
It is not solved as a proportion because it is a sum of cars and trucks.
Cars + Trucks = Total Vehicles
Car to truck ratio is 6:3
Cars can be represented by 6x.
Trucks can be represented by 3x
Cars + Trucks = Total Vehicles
6x + 3x = 81
Add up 6x + 3x.
9x = 81
Divide by 9.
x = 9
You are not done here.
The number of cars is represented by 6x.
6x = 6(9)
6x = 54
There are 54 cars.
Did you know how to solve this problem?
