Question

11 more than five of a certain number is twenty more than 2 times of that number.What is the number?

Answer 1

Let the number =x
11 more than 5 of a number =5x+11---(1)
20 more than 2 times of the number
=2x+20---(2)
(1)=(2)
5x+11=2x+20
5x-2x=20-11
3x=9
x=9/3
x=3
Therefore the required number =x=3

Answer 2

 Let the number be x

Given: 

11 + 5x = 20 + 2x

5x - 2x = 20 - 11

3x = 9

x = 3

The number is 3.