I have the answer to this problem already but I solved it using guess-and-check.
What's the most concise way to solve this prob?
Wayne is building a shed in his backyward to store his snowmobile. Value Hardware sells 3-in finishing nails for $.99/lb. and 2-in finishing nails for $1.39/lb. Wayne needs 5 lbs of nails. If his bill totals $6.15, how many pounds of each size did he buy?
2007-09-17 14:48:54 · 3 answers · asked by 2 days after my B day :) 2 in Science & Mathematics ➔ Mathematics
Make equations out of the information given.
Let x be the number of 3-inch finishing nails in pounds
Let y be the number of 2-inch finishing nails in pounds
The total weight is 5 pounds so x+y = 5
the total price is $6.15, so 0.99x + 1.39y = 6.15
Solve this system of 2 equations in 2 unknowns to get your answer.
2007-09-17 14:58:29 · answer #1 · answered by Demiurge42 7 · 0⤊ 0⤋
Let x = pounds of 3" nails
Then (5-x) = pounds of 2" nails
Then $.99x + $1.39(5-x) = $6.15 and solve algebraically for x.
2007-09-17 14:55:46 · answer #2 · answered by Tom K 6 · 0⤊ 0⤋
say he bought x pounds of 2" nails and y pounds of 3" nails
then he paid 99x +139y = 615
and also x + y = 5
so x = 5 - y
and 99(5 - y) +139y =615
495 - 99y +139y = 615
y = 3
x = 2
2007-09-17 14:58:34 · answer #3 · answered by goatfish 1 · 0⤊ 0⤋