. 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
official answer is E but can't figure the answer out.
My equations set up were
h=hamburger
c=coleslaw
f=French fries
h+c=3.59
h+f=4.40
f=2c
multiply the 1st equation by -1 to get rid of the h
we then get f-c= .81 therefore f=.81+c
substitute for f in 3rd equation
.81+c=2c
.81=c
f=2..81
=1.62
(A) $0.30
(B) $0.45
(C) $0.60
(D) $0.75
(E) $0.90
official answer is E but can't figure the answer out.
My equations set up were
h=hamburger
c=coleslaw
f=French fries
h+c=3.59
h+f=4.40
f=2c
multiply the 1st equation by -1 to get rid of the h
we then get f-c= .81 therefore f=.81+c
substitute for f in 3rd equation
.81+c=2c
.81=c
f=2..81
=1.62
