SOLUTION: Alec is ten years older than his sister, Alisa. Alec is also twice as old as his brother, Ivan. How old is each sibling if the sum of their ages is 50? Use 5 Step Problem Solving

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Question 344378: Alec is ten years older than his sister, Alisa. Alec is also twice as old as his brother, Ivan. How old is each sibling if the sum of their ages is 50? Use 5 Step Problem Solving
Answer by Fombitz(32388) About Me  (Show Source):
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A-Alec
B-Alisa
C-Ivan
.
.
1.A=B%2B10
2.A=2C
3.A%2BB%2BC=50
From eq. 1,
B=A-10
From eq. 2,
C=A%2F2
Substitute both results into eq. 3,
A%2B%28A-10%29%2BA%2F2=50
Multiply both sides by 2,
2A%2B2%28A-10%29%2BA=100
2A%2B2A-20%2BA=100
5A-20=100
5A=120
highlight%28A=24%29
Then
B=24-10
highlight%28B=14%29
And finally,
C=24%2F2
highlight%28C=12%29
.
.
.
Alec is 24, Alisa is 14, and Ivan is 12.