In the monthly payment formula r is the percentage rate as a decimal.
To turn a percentage into a decimal, move the decimal point 2 places to the left.
5.7% becomes 0.057
x = liters of 40% solution
y = liters of 70% solution
Gabe needs 30 liters, so
x + y = 30
Each liter of 40% solution contributes 0.4x liter of acid; each liter of 70% solution contributes 0.7y liter of acid. Gabe needs a solution with concentration 60%, which from 30 liters amounts to a net volume of 0.6*30 = 18 liters of acid. So
0.4x + 0.7y = 18
Solve the system however you like. By substitution, we have
y = 30 - x
0.4x + 0.7(30 - x) = 18
0.4x + 21 - 0.7x = 18
3 = 0.3x
==> x = 10 ==> y = 20
Answer:
5 chores
Step-by-step explanation:
3+2x=13
3+2(5)=13
She would have to do 5 chores in order to earn enough money.
59.346
V = pi * r^2 * h
V = 3.14 * 3^2 * 2.1
V = 3.14 * 9 *2.1
V = 3.14 * 18.9
V = 59.346
Answer:A=8-1/57=455/57=7.98
Step-by-step explanation:
