Answer:
C
Step-by-step explanation:
Given that he has sold 40% then he still has to sell (100 - 40)% = 60%
60% of 70
=
× 70 = 0.6 × 70 = 42 → C
Answer:
4.5 % alloy
Step-by-step explanation:
Let x = amt of 30% alloy
The resulting total is to be 25 oz, therefore:
(25-x) = amt of 5% alloy:
A typical mixture equation:
.30x + .05(25-x) = .20(25)
.30x + 1.25 - .05x = 5 .30x - .05x = 5 - 1.25
.25x = 3.75
x = 3.75%2F.25
x = 15 oz of 30% alloy required
then
25-15 = 10 oz of 5% alloy:
Check solution
.30(15) + .05(10) = .20(25)
4.5 + .5 = 5
If i had to estimate i would say letter D
12 is 1 more than 11
12 is one less than 13
this ok?