Step-by-step explanation:
If x = the amount of 12% and y = the amount of 20%, then x + y = 80
Since we need 80 grams of 15%, 80(.15) = 12.
We are given that .12x + .20y = 12.
We can solve the first equation for x or y. Let's do x.
x = 80 - y
.12(80 - y) + .20y = 12
9.6 - .12y + .20y = 12
.08y = 2.4
y = 30
x = 80 - 30 = 50
To get from 8.4 to 10 in multiplication, we need to multiply 8.4 by 10/8.4
That means that if we multiply 30 by 10/8.4 we get the answer
which is 35,714
The same with the other
8.4 times 100/30 = 28
Answer:seventh year
Step-by-step explanation:
