The ratio of sports cars to the total number of cars on display in Ken's car shop was 3 : 10. ²₇ of the remaining cars on display were electric cars and the rest were saloon cars and family cars in the ratio of 5 : 4. If there were 18 more sports cars than saloon cars, how many family cars were there?

Sports Cars	Electric Cars	Saloon Cars	Family Cars	Total Cars
3x9	7x9			10x9
	2x9	5x9		7x9
		5x5	4x5
27 u	18 u	25 u	20 u

The total number of saloon cars and family cars is the combined repeated identity. Make the total number of saloon cars and family cars the same. LCM of 5 and 9 is 45.

The total number of electric cars, saloon cars and family cars is the next combined repeated identity. Make the total number of electric cars, saloon cars and family cars the same. LCM of 7 and 7 is 63. 

Number of more sports cars than saloon cars
= 27 u - 25 u
= 2 u

2 u = 18

1 u = 18 ÷ 2 = 9

Number of family cars
= 20 u
= 20 x 9
= 180

Answer(s): 180