SOLUTION: tasha bought salads at $2.75 each and cartons of milk at $.80 each. the total cost was $16.15. she bought 8 items, how many of each did she buy ?

Algebra ->  Customizable Word Problem Solvers  -> Evaluation -> SOLUTION: tasha bought salads at $2.75 each and cartons of milk at $.80 each. the total cost was $16.15. she bought 8 items, how many of each did she buy ?      Log On

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Question 504009: tasha bought salads at $2.75 each and cartons of milk at $.80 each. the total cost was $16.15. she bought 8 items, how many of each did she buy ?
Found 2 solutions by oberobic, josmiceli:
Answer by oberobic(2304) About Me  (Show Source):
You can put this solution on YOUR website!
s = number of salads purchased
275s = value of the salads in cents
m = number of cartons of milk purchased
80m = value of the milk in cents
.
275s + 80m = 1615
.
s + m = 8
so
s = 8-m
.
substitute
.
275(8-m) + 80m = 1615
2200 -275m + 80m = 1615
.
collect terms and tidy up
.
-195m = -585
m = 3
.
She bought 3 cartons of milk.
.
s = 8-m
s = 5
.
She bought 5 salads.
.
Always check your work.
.
5(275) = 1375
3(80) = 240
1375 + 240 = 1615
Correct.
.
Answer: Tasha bought 3 cartons of milk and 5 salads.
.
Done.

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let a = number of salads bought
Let b = number of cartons of milk bought
given:
(1) +a+%2B+b+=+8+
(2) +275a+%2B+80b+=+1615+ (in cents)
----------------------
Multiply both sides of (1) by 80 and
subtract (1) from (2)
(2) +275a+%2B+80b+=+1615+
(1) +-80a+-+80b+=+-640+
+195a+=+975+
+a+=+5+
and, since
(1) +a+%2B+b+=+8+
(1) +5+%2B+b+=+8+
(1) +b+=+3+
5 salads were bought
3 cartons of milk were bought
check answer:
(2) +275a+%2B+80b+=+1615+
(2) +275%2A5+%2B+80%2A3+=+1615+
(2) +1375+%2B+240+=+1615+
(2) +1615+=+1615+
OK