Question

Mean of 3 number is 50 if 2 of them are 30 and 50 what is the third number

Answer 1

Mean=30
Mean =sum of observation /no. of observation
Let third no. BE x
So,
30=30+50+x/3
90=80+x
X=90-80
X=10

Answer 2

dude here is solution:

mean of 3 number = 50

two numbers are 30 , 50

let the  3rd number be x

so according to question :

50=30+50+x/3

50*3=80+x

150 - 80=x

70 = x

therefore third number is 70