The ratio of family 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 sports cars and electric cars in the ratio of 9 : 7. If there were 228 more family cars than sports cars, how many electric cars were there?

Family Cars	Saloon Cars	Sports Cars	Electric Cars	Total Cars
4x16	7x16			11x16
	2x16	5x16		7x16
		9x5	7x5
64 u	32 u	45 u	35 u

The total number of sports cars and electric cars is the combined repeated identity. Make the total number of sports cars and electric cars the same. LCM of 5 and 16 is 80.

The total number of saloon cars, sports cars and electric cars is the next combined repeated identity. Make the total number of saloon cars, sports cars and electric cars the same. LCM of 7 and 7 is 112. 

Number of more family cars than sports cars
= 64 u - 45 u
= 19 u

19 u = 228

1 u = 228 ÷ 19 = 12

Number of electric cars
= 35 u
= 35 x 12
= 420

Answer(s): 420