SOLUTION: An ice cream stand sells single-dip cones for $1.75 and double-dip cones for $2.25. Yesterday, 500 cones were sold for $900. How many single-dip and how many double-dip cones were

Algebra ->  Real-numbers -> SOLUTION: An ice cream stand sells single-dip cones for $1.75 and double-dip cones for $2.25. Yesterday, 500 cones were sold for $900. How many single-dip and how many double-dip cones were       Log On


   

Question 174604: An ice cream stand sells single-dip cones for $1.75 and double-dip cones for $2.25. Yesterday, 500 cones were sold for $900. How many single-dip and how many double-dip cones were sold?
Found 2 solutions by Mathtut, Earlsdon:
Answer by Mathtut(3670) About Me  (Show Source):
You can put this solution on YOUR website!
let the number of single and double cones sold, be s and d respectively
:
s+d=500............eq 1
1.75s+2.25d=900....eq 2
:
re write eq 1 to s=500-d and plug that value into eq 2
:
1.75(500-d)+2.25d=900
:
875-1.75d+2.25d=900
:
.5d=25
:
highlight%28d=50%29number of doubles sold
:
highlight%28s=500-50=450%29number of singles sold

Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
Let S = the number of single-dip cones sold and D = the number of double-dip cones sold.
From the problem description, you can write:
1) S+D = 500 "...500 cones were sold..." Rewrite this equation as S = 500-D and substitute into equation 2) for S.
2) 1.75(S) + 2.25(D) = 900 "...for $900."
2a) 1.75(500-D)+2.25(D) = 900 Simplify this and solve for D.
2b) 875-1.75D+2.25D = 900 Subtract $875 from both sides.
2c) -1.75D+2.25D = 25 Combine like-terms.
0.5D = 25 Divide both sides by 0.5
D = 50 This is the number of double-dip cones sold.
S = 500-D
S = 500-50
S = 450 This is the number of single-dip cones sold.