Problem Solving

Hello

The answer is E) but my answer for French fries was $1.62.... Can anyone explain?


At a certain diner, a hamburger and coleslaw cost $3.59, and a hamburger and french fries cost $4.40. If french fries cost twice as much as coleslaw, how much do french fries cost?
(A) $0.30
(B) $0.45
(C) $0.60
(D) $0.75
(E) $0.90

Let the price of coleslaw be C
Then price of french fries is 2*C (given)
Let the price of Hamburger be H

now H+C=3.59
H+2C= 4.40

which gives C= 0.81
And price of French fries = 2*C =1.62

There is nothing wrong with your solution if the question is the same

So, do you think the answer E) is wrong?? I am confused..

dunkin77 wrote:So, do you think the answer E) is wrong?? I am confused..

E is wrong if the question is exactly like what you have posted

Okay - thanks for the confirmation!

let the cost of a hamburger be 'ham', the cost of a fresh fries be 'fri' and the cost of coleslaw be 'col'.
from the question,
ham + col= $3.59 ------(i)
ham + fri= $4.40 ---------(ii)
fri= 2*col.= 2col --------(iii)
from i, ham = $3.59- col
from ii, ham = $4.40-fri
since the price of ham in both is the same, then
ham= 3.59-col = 4.40-fri
3.59-col = 4.40 - fri
fri-col = 0.81
but from equation iii, col= fri/2
therefore,
$$fri-\frac{fri}{2}=0.81$$
$$2fri-fri=1.62$$
$$fri=1.62$$
$$Therefore,\ french\ fries\ \cos t=$1.62$$

dunkin77 wrote:Hello

The answer is E) but my answer for French fries was $1.62.... Can anyone explain?


At a certain diner, a hamburger and coleslaw cost $3.59, and a hamburger and french fries cost $4.40. If french fries cost twice as much as coleslaw, how much do french fries cost?
(A) $0.30
(B) $0.45
(C) $0.60
(D) $0.75
(E) $0.90

Hi dunkin77,

The correct answer is $1.62.
Answer choices seems incorrect.

If E is the correct answer, then the cost of one hamburger and French fries must be $4.04, not $4.40.