Answer:
Step-by-step explanation:
Let q represent the number of quarters Theresa has. Then the value of her coins is ...
0.25q + 0.10(20 -q) = 2.75
0.15q = 0.75 . . . . . . . . . subtract 2.00, collect terms
q = 0.75/0.15 = 5
Theresa has 5 quarters and 15 dimes.
So we know the tank already has 5 gallons and we need 9. This means we need 4 more gallons in order to fill up the tank.
If 1/4 gallon is being filled per minute we need to find out how many 1/4 gallons makes up 4 gallons in total.
4 of the 1/4 gallons makes up 1 whole gallon. So since we need 4 whole gallons we would need 16 of the 1/4 gallons.
This means that it will take 16 minutes for the tank to hold 9 gallons of water.
Answer:
Step-by-step explanation:
You need to set up a proportion.
(21 - 15) / 21 = 4/(x + 4)
6 / 21 = 4/(x + 4)
2/7 = 4/(x + 4)
2(x + 4) = 7*4
2x + 8 = 28
2x + 8-8= 28 - 8
2x = 20
x = 20/2
x = 10
