The ratio of family 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 sports cars and the rest were saloon cars and electric cars in the ratio of 6 : 5. If there were 70 more family cars than saloon cars, how many electric cars were there?

Family Cars	Sports Cars	Saloon Cars	Electric Cars	Total Cars
2x11	5x11			7x11
	3x11	2x11		5x11
		6x2	5x2
22 u	33 u	12 u	10 u

The total number of saloon cars and electric cars is the combined repeated identity. Make the total number of saloon cars and electric cars the same. LCM of 2 and 11 is 22.

The total number of sports cars, saloon cars and electric cars is the next combined repeated identity. Make the total number of sports cars, saloon cars and electric cars the same. LCM of 5 and 5 is 55. 

Number of more family cars than saloon cars
= 22 u - 12 u
= 10 u

10 u = 70

1 u = 70 ÷ 10 = 7

Number of electric cars
= 10 u
= 10 x 7
= 70

Answer(s): 70