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| Math Central | Quandaries & Queries |
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Question from sujan, a student: The average age of a group of 10 students was 20. The average age increased by 2 years when two new students joined the group . What is the average age of the two new students who joined the group? |
Hi,
Suppose the total of the ages of the 10 students is $T$ years then
\[\frac{T}{10} = 20.\]
What is $T?$
What is the total of the ages of the 12 students?
Penny
When we say the average age of the first 10 students is 20, this means that (A1 + A2 + ... + A10) / 10 = 20
What is (A1 + A2 + ... + A10)?
Write out an equation that says that the average age of the 12 students is 22.
What is (A1+A2+...+A10+A11+A12)?
What is A11 + A12?
What is the average of A11 and A12?
Good Hunting!
RD
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