Question 1131176: Elizabeth is twice as old as cathrine. If seven years ago the sum of their ages was 82, how old are they now? Found 2 solutions by htmentor, MathLover1:Answer by htmentor(1343) (Show Source):
You can put this solution on YOUR website! Let E = Elizabeth's age, C = Cathrine's age
Elizabeth is twice as old as Cathrine:
E = 2C
Seven years ago their ages were E - 7 and C - 7 and their sum was 82:
E - 7 + C - 7 = 82
Substitute for E from the 1st equation:
2C - 7 + C - 7 = 82
3C = 96
C = 32
Thus Cathrine is 32 and Elizabeth is 64
You can put this solution on YOUR website!
let Elizabeth's age be and Catherine's age be
if Elizabeth is twice as old as Catherine, we have
.........eq.1
seven years ago:
.....Elizabeth's age
......Catherine's age
If seven years ago the sum of their ages was , we have
..-> substitute from eq.1
find .........eq.1
how old are they now: Elizabeth is and Catherine is
