The ratio of sports cars to the total number of cars on display in Ken's car shop was 4 : 11. ²₇ of the remaining cars on display were saloon cars and the rest were family cars and electric cars in the ratio of 2 : 1. If there were 28 more sports cars than family cars, how many electric cars were there?

Sports Cars	Saloon Cars	Family Cars	Electric Cars	Total Cars
4x3	7x3			11x3
	2x3	5x3		7x3
		2x5	1x5
12 u	6 u	10 u	5 u

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

The total number of saloon cars, family cars and electric cars is the next combined repeated identity. Make the total number of saloon cars, family cars and electric cars the same. LCM of 7 and 7 is 21. 

Number of more sports cars than family cars
= 12 u - 10 u
= 2 u

2 u = 28

1 u = 28 ÷ 2 = 14

Number of electric cars
= 5 u
= 5 x 14
= 70

Answer(s): 70