1 part almond
2 parts walnut
3 parts raisins
6 parts in all.
almond = 12 per pound
walnuts = 9 per pound
raisins = 5 per pound
1/6 12 = 2
2/6 9 = 3
3/6 5 = 2.5
total 7.5
15/7.5 = 2
almond: 2 2 = 4 ⇒ 4/12 = 1/3 pounds of almonds
walnut: 3 2 = 6 ⇒ 6/9 = 2/3 pounds of walnuts
raisins: 2.5 2 = 5 ⇒ 5/5 = 1 pound of raisins
1/3 + 2/3 + 1 ⇒ 1/3 + 2/3 + (1 *3/3) = 1/3 + 2/3 + 3/3 = 6/3 = 2 pounds of trail mix.