<span>Jerry is 8 years younger than Patricia, so:
(1): Jerry = Patricia - 8
Six years ago, Patricia was 3 times as old as Jerry was then, so:
(2): (Patricia - 6) = (Jerry - 6)*3
Putting equation 1 in to equation 2
(Patricia - 6) = (Patricia - 8 - 6)*3
Patricia - 6 = 3Patricia - 42
36 = 2Patricia
Patricia = 18
And so Jerry = 10</span>
Divide total cups he drank by the # of cups in each bottle.
7 ÷ 3= 2.3333
Since each bottle only holds 3 cups, he drank 3 bottles of water. He didn't drink all the water in the third bottle, but he started drinking the third bottle.
ANSWER: 3 bottles
Hope this helps! :)