The mean of two number is 13. If one of them is 20, find out the other

1.	The mean of two number is 13. If one of them is 20, find out the other
Answer» Given The mean of two numbers is 13 one number is 20 To Find the other number $\sf\huge\bold{\underline{\underline{{Solution}}}}$ Formula for finding mean: $\sf \boxed{\bold{Mean = \dfrac{sum \: of \: the \: terms}{no.of \:terms }} }$ Let the SECOND number be 'x' According to the question There are two terms or numbers say 23 and x and no.of terms is 2 $\sf \: Mean = \dfrac{23 + x}{2}$ $\sf \longmapsto20 = \dfrac{23 + x}{2}$ Cross MULTIPLY to both SIDES : $\sf \longmapsto23 + x = 20 \times 2$ $\sf \longmapsto23 + x = 40$ $\sf \longmapsto \: x = 40 - 23$ $\sf \longmapsto \: x = 17$ $\sf \bold{x = 17}$ ∴The other number is 17 Check:- Mean =23+17/2 Mean=40/2 Mean=20

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