Question

a scientist has two solutions , which she has labeled solution A and solution B. Each contains salt. she knows that solution A is 30% salt. she want to obtain 50 ounces of a mixture that is 75% salt. how many ounces of each solution should she use

Answer 1

the As given,

The total mixture is 50 oz. Therefore, we can write

A + B = 50 (i)

30% salt in solution A = 30% of A = 30/100 * A = 0.3A

80% salt in solution B = 80% of B = 80/100 * B = 0.8*B

75% salt in total solution = 75% of 50 = 75/100 * 50 = 0.75(50)

Therefore, we can write

0.3A + 0.8B = 0.75(50) (ii)

From equation (i), we can write A = 50 - B and put it in equation (ii)

0.3(50 - B) + 0.8B = 0.75(50)

15 - 0.3B + 0.8B = 37.5

0.5B = 37.5 - 15

0.5B = 22.5

B = 22.5/0.5

B = 45 oz

Also, using equation (i)

A + B = 50

A + 45 = 50

A = 50 - 45

A = 5 oz

Therefore, the quantity of first solution would be 5 oz and the quantity of the second solution would be 45 oz.