Average of ten positive numbers is x If each number is increased by 10%, then x:

Let 10 numbers be x1, x2, x3 ….. x10
According to question average of these 10 numbers is 10.

⇒ (x1 + x2 + x3 + …….. + x10)/10 = x

Now if each number is increased by 10%, then new average, say y,

y = (1.1 x1 + 1.1 x2 + 1.1 x3 + ……… + 1.1 x10)/10
⇒ y = 1.1 × ({x1 + x2 + x3 + …….. + x10}/10)
⇒ y= 1.1 x
⇒ y is 10% increased.