Question 91657
Carl is A years old.
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His sister is twice his age (2A) plus 6 years. So she is 2A + 6.
.
To average their two ages, add their ages together and divide by 2. Adding their ages results
in:
.
A + 2A + 6 = 3A + 6
.
Then dividing by 2:
.
{{{Average Age=(3A + 6)/2 }}}
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If you would like you can also divide each of the terms in the numerator by 2 and express the
answer as:
.
{{{Average Age = (3/2)A + 6/2 = (3/2)A + 3}}}
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Hope this helps you to understand the problem a little better.