Q18: A

A certain company that sells only cars and trucks reported that revenues from car sales in 1997 were down 11 percent from 1996 and revenues from truck sales in 1997 were up 7 percent from 1996. If total revenues from car sales and truck sales in 1997 were up 1 percent from 1996, what is the ratio of revenue from car sales in 1996 to revenue from truck sales in 1996?

A. 1 : 2

B. 4 : 5

C. 1 : 1

D. 3 : 2

E. 5 : 3

please help!!!!

cars:S1996（1-11%）=S1997

trucks:S1996(1+7%) =S1997

sum:S1996(1+1%)=S1997

设car占1-X%，truck占X%

1.07*x%+0.89*(1-x%)=1.01

得到：car 占1/3 truck 2/3

所以car/truck=1/2

选A