Due to the recession, a show room reported that revenue from luxury car sales were down by 11% and revenue from economy car sales were up by 7% . If the total revenue were up by 1% then what is the ratio of revenue from luxury car sales to revenue from economy car sales ?

Correct Answer: 1:2
Let the usual revenues be L and E respectively. So, total usual revenue is (L + E). New revenue from luxury car sales = L - 11% of L = L - 0.11L = 0.89L New revenue from economy car sales = E - 7% of E = E - 0.07E = 1.07E New total revenue = 0.89L + 1.07E ATQ,   {(0.89L + 1.07E) - (L + E)} / (L + E) = 1/100 or,  100(0.89L + 1.07E - L - E) = L + E or,  100(0.07E - 0.11L) = L + E or,  7E - 11L = L + E or.  11L + L = 7E - E or,  12L = 6E or,  L/E = 6/12 = 1/2 or,  L : E = 1 : 2