Question

Seed mixture X is 40 percent ryegrass and 60 percent bluegrass by weight; seed mixture Y is 25 percent ryegrass and 75 % fescue. If a mixture of X and Y contains 30% ryegrass, what percent of the weight of the mixture is X?

A. 10%
B. 331/3%
C. 40%
D. 50%
E. 662/3%

Answer 1

B) 33 1/3%

Explanation:

X contains 40% ryegrass and 60% bluegrass.

Y contains 25% ryegrass and 75% Gracie.

Mixture of X and Y contains 30% ryegrass

Assume weight of mixture = 100g

Weight of ryegrass = 30g

Assume weight of X used is Xg, the weight of mixture Y used would be (100 - X)g

Equate ryegrass in the mixture

0.4X + 0.25(100 - X) = 30

0.4X + 0.25(100) - 0.25(X) = 30

0.4X + 25 - 0.25X = 30

0.4X - 0.25X = 30 - 25

0.15X = 5

X = 5/0.15

X = 33.3 = 33 1/3

weight of mixture X asap percentage of the mixture = (weight of X / weight of mixture) 100

= 33 1/3 * 100

= 33 1/3%