alivapriyada wrote:A coffee cart make $2,400 in revenue. If a large cup of coffee costs twice as much as a small cup, the cart sold 950 large cups, and it sold nothing besides the two sizes, then how many small cups of coffee did it sell?
(1) A large cup of coffee costs $2
(2) If the cart had sold 20% fewer small cups, its revenue would have been reduced by 4 1/6%.
Book Answer is (D). I'm not sure how statement No. 2 is sufficient.
given small cup cost=x
large cup cost 2x
let a be number of large cup sold
let b be number of small number of cup sold
a+b=950 ----- eq(1)
a*2x+b*x=2400 --- eq2
so basically we need to solve 4 variable so we should have 4 equation
let see statement 1)A large cup of coffee costs $2
so now we know 2x=2 so x=1
so we have two equation a+b=950
substituting value of x in eq 2 w e get 2a+b=2400 so 2 variable 2 equation thus statement 1 is sufficient
lets c statement 2)If the cart had sold 20% fewer small cups, its revenue would have been reduced by 4 1/6%.
so 20% fewer smaller up so now smaller cup sold 0.8b
large cup sold remain a
revenue decrease by 25/6 %
so new revenue 2400 - 25/6%of 2400 let say this 2000( i have assumed some random value)
so new equation will be a+0.8b=2000 ----- eq 3
s now we have 2 equation one equation 2 and eq 3
again we can solve
so statement 2 is sufficient
hence D
Ideation without execution is delusion
