SOLUTION: Deanna is twice as old as her brother. If the difference in their ages is 7 years, how old is Deanna?

Question 522132: Deanna is twice as old as her brother. If the difference in their ages is 7 years, how old is Deanna?
Answer by Maths68(1474) (Show Source): You can put this solution on YOUR website!
Let
Present age of Deanna = d
Present age of Borther = b

Deanna is twice as old as her brother.
d=2b .......(1)
The difference in their ages is 7 years
d-b=7..........(2)
Plug in the value of d from (1) to (2)
2b-b=7
b=7
Plug in the value of b in (1)
d=2b
d=2*7
d=14
Deanna is 14 and her brother is 7 years old
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