The ratio of family cars to the total number of cars on display in Ken's car shop was 2 : 7. ²₅ of the remaining cars on display were saloon cars and the rest were electric cars and sports cars in the ratio of 3 : 2. If there were 7 more family cars than electric cars, how many sports cars were there?

Family Cars	Saloon Cars	Electric Cars	Sports Cars	Total Cars
2x5	5x5			7x5
	2x5	3x5		5x5
		3x3	2x3
10 u	10 u	9 u	6 u

The total number of electric cars and sports cars is the combined repeated identity. Make the total number of electric cars and sports cars the same. LCM of 3 and 5 is 15.

The total number of saloon cars, electric cars and sports cars is the next combined repeated identity. Make the total number of saloon cars, electric cars and sports cars the same. LCM of 5 and 5 is 25. 

Number of more family cars than electric cars
= 10 u - 9 u
= 1 u

1 u = 7

1 u = 7 ÷ 1 = 7

Number of sports cars
= 6 u
= 6 x 7
= 42

Answer(s): 42