Question

find three conescutive whole number whose sun is more than 45 but less than 54

Answer 1

Let's take 3 consecutive numbers as x, x + 1 , x + 2

Sum , S = x + x + 1 + x + 2 = 3x + 3

So according to question,

S > 45 and S < 54

When S > 45 :

3( x + 1 ) > 45

x + 1 > 15

x > 14

When S < 54 :

3(x + 1 ) < 54

x + 1 < 18

x < 17

So x should be between 14 and 17 , I.e 14< x < 17

So 3 consecutive numbers are 15,16,17