trucks

magical cook wrote:A total n trucks and cars are parked in alot. if the number of cars is 1/4 the numbner of trucks, and 2/3 of the trucks are pickups. how many pickups, in terms of n, are parked in the lot?

a. 1/6n

b. 5/12n

c. 1/2n

d. 8/15n

e. 11/12n

Let the number of trucks n cars = 60, Now let us assume out of 60 4*x are trucks, then the number of cars are 1/4 th 4*x = x

So we get 4*x+x = 60, that is x =12, so the number of trucks are 4*x= 48 and the number of pickups are 2/3 rd this number = 2/3*48= 32,

So the pickups are 8/15 times 60, that is the number of pickups are 8/15 times n (the number of vehicles in the parking lot)

Regards

THANKS GABRIEL

my logic is some sort of bizarre but....

we can solve this plunging at the answers

but firts we need to find a common number to work with (is easier):
1/4 x 2/3 = whatever / 12 (common denominator) so we can work with 12 as a total of trucks or to make it easier we can work with 120.

cars= 120 x 1/4 = 30
pickups= 120 x 2/3 =80
rest of trucks 120 x 1/3 or 120- 80 = 40

now the total is cars + pickups + rest of trucks =150

so 150=n

only plung on the answers

for example
d)
8/15 x 150 = 80 (pickups) in this case this is the answer d