The ratio of sports cars to the total number of cars on display in Ken's car shop was 2 : 7. ³₅ of the remaining cars on display were saloon cars and the rest were electric cars and family cars in the ratio of 5 : 4. If there were 24 more sports cars than electric cars, how many family cars were there?

Sports Cars	Saloon Cars	Electric Cars	Family Cars	Total Cars
2x9	5x9			7x9
	3x9	2x9		5x9
		5x2	4x2
18 u	27 u	10 u	8 u

The total number of electric cars and family cars is the combined repeated identity. Make the total number of electric cars and family cars the same. LCM of 2 and 9 is 18.

The total number of saloon cars, electric cars and family cars is the next combined repeated identity. Make the total number of saloon cars, electric cars and family cars the same. LCM of 5 and 5 is 45. 

Number of more sports cars than electric cars
= 18 u - 10 u
= 8 u

8 u = 24

1 u = 24 ÷ 8 = 3

Number of family cars
= 8 u
= 8 x 3
= 24

Answer(s): 24