Problem Solving

Hi there ,

please help me to understand this quastion soulution
:



Four brothers Adam, Bill, Charles and David together contributed certain amount of money and purchased a car. The contribution made by Adam is half that of the total contribution made by the other three brothers, contribution made by Bill is one-fourth of the total contribution made by the other three brothers and the contribution made by Charles is two-third of the total contribution made by the other three brothers. If the total price of the car is $9900, find the contribution made by David.

Answer Choices


A. $540

B. $580

C. $600

D. $660

E. $680

the right answer is D, please explain in details .

Tnx

Let total (t) = a +b + c + d. We know that t = 9900, but lets keep it t for now

a = (b+c+d)/2 = (t-a)/2, so a = t/3

Similarly

b = (t-b)/4, so b = t/5

c = (t-c)x 2/3 = 2t/5

Putting it back in original equation, we have

d = t - (a + b + c)
= t - (t/3 + t/5 + 2t/5)
= 9900 - 3300 - 1980 - 3960
= 9900 - 9240
= 660

Tnx for your reply,

please explain as most as you can, i missed something :

a = (b+c+d)/2 = (t-a)/2, so a = t/3


i dont get it how you get to a=t/3 ,

i got it , no need for a reply... full me