PP-T2-DS140

[little8]

140. 14610-!-item-!-187;#058&010398
A manufacturer produced x percent more video cameras in 1994 than in 1993 and y percent more video cameras in 1995 than in 1994. If the manufacturer produced 1,000 video cameras in 1993, how many video cameras did the manufacturer produce in 1995 ?

(1) xy = 20
(2) x + y + (xy)/100 = 9.2
B

算了很多便,還是想不通..
懇請大大解題哩~~

[amazingslim]

94=93(1+(x/100))
95=94(1+(y/100))

so 95=93(1+(x/100))(1+(y/100))
=1000(1+(x/100))(1+(y/100))
=1000(1+(x/100)+(y/100)+(xy/10000))
=1000(1+(x+y/100)+(xy/10000))


(2) x + y + (x+y)/100 = 9.2
=> (x+y)/100+(xy/10000) =0.092