Answer:
10
Explanation:
Let's call Ahmed's number x,
- If he multiplies it by 2, it becomes 2x
- He then divides it by 5 so it would be 2x ÷ 5
- The result was 4, so it would be written as 2x ÷ 5 = 4
To solve for x,
- First, multiply both sides by 5: 2x = 20
- Finally divide both sides by 2 to get x on its own: x = 10
- Answer: He was thinking of the number 10
You could also work backwards:
If he ×2 then ÷5, you would ×5 then ÷2 (doing the opposite):
Hope this helps!