[求助]天山 7-Q28

wanders

天山 7-Q28 math

A total of n trucks and cars are parked in a slot. If the number of cars is 1/4 the number of trucks, and 2/3 of the trucks are pickups, how many pickups, in terms of n, are parked in the slot?

A. 1/6n B.5/12n C.1/2n D.8/15n E.11/12n

ANS

問這題是很笨,,but,,我就是算不出來

mikejia

car:truck =1:4  则卡车占 4/5，乘2/3得结果。

himba

假设有x个t，那么就有1/4x个c，2/3x个p

x+1/4x=n

x=4/5n

p:2/3x=2/3*4/5n=8/15n