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Mr and Mrs. Wilson have 3 children: Jessica, Jeremy, and Jenna. The average of Jessica and Jeremy's age is 11. The average of all three children's ages is 10 . How old is Jenna?

 Aug 27, 2021
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Mr and Mrs. Wilson have 3 children: Jessica, Jeremy, and Jenna. The average of Jessica and Jeremy's age is 11. The average of all three children's ages is 10 . How old is Jenna?

 

Hello Guest!

 

\(\frac{js+jr}{2}=11\ |\ \cdot 2\\ js+jr=22\\ \dfrac{js+jr+jn}{3 }=10\ |\ \cdot 3\\ js+jr+jn=30\ | -jn\\ js+jr=30-jn\)

\(22=30-jn\\ jn=30-22\)

\(jn=8\)

 

Jenna is 8.

laugh  !

 Aug 28, 2021

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