Newaz111 wrote:Chris mixed 3 pounds of raisins with 4 pounds of nuts. If a pound of nuts costs 3 times as much as a pound of raisins, then the total cost of the raisins was what fraction of the total cost of the mixture?
A.3/7
B.1/3
C.1/4
D.1/5
E.1/7
A fast approach is to choose some nice values for the per-pound costs.
Let the raisins cost $1 PER POUND
This mean the nuts cost $3 PER POUND
[since a pound of nuts costs 3 times as much as a pound of raisins]
3 pounds of raisins costs (3 pounds)($1/pound) =
$3
4 pounds of nuts costs (4 pounds)($3/pound) =
$12
TOTAL COST =
$3 +
$12 =
$15
The total cost of the raisins was what fraction of the total cost of the mixture?
$3/
$15 = [spoiler]1/5 = D[/spoiler]
Cheers,
Brent
