You use about 15 gallons of water when you shower. if you take 20% less time when you shower, estimate how many gallons of water you would use in a week if you took a shower a day.
a. 100
b. 85
c. 40
d. 20

With finding limits of multi variable !

Someone answer asap for ! the following statements are true about the coins calvin and sasha have collected. * calvin and sasha has the same amount of money. * calvin has only quarters. * sasha has dimes, nickels, and pennies * calvin has the same number of quarters as sasha has dimes. * sasha has $1.95 in coins that are not dimes. exactly how many quarters does calvin have?

Ithink i know it but i want to be sure so can you me out ?