Question

the average of 18, 27 and another number is 30 what is the third number

Answer 1

Let the third number be x.

Average
= sum of the items / No. of items

30 = (18+27+x) /3

90 = 45 + x

x = 45

I hope this answer helps you

Answer 2

HELLO DEAR,

let the third no. be x.

we know, average of no. = $\large{\bold{\frac{sum\:\: of\:\: the \:\:no. }{total\;\; no.}}}$

now, two no. Is given and average of the three no. Is 30.

$\bold{\frac{18 + 27 + x}{3} = 30}$

$\bold{45 + x = 90}$

$\bold{x = 90 - 45 = 45}$

$\bold{x = 45}$

Hence, the third no. is 45.


I HOPE ITS HELP YOU DEAR,
THANKS