Question

What number: When decreased by 40% becomes 480?

Answer 1

Let the number be = 100

Decrease = 40% = 40

∴ Decreased number = 100 - 40 = 60

If decreased number is 60, then original number = 100

and if decreased number is 480, then original number `= 100/480 xx 60 = 800`

Answer 2

When the number is decreased by 40%, it becomes 480. Mathematically:

x − 0.4x = 480

Factor out x on the left-hand side:

x(1 − 0.4) = 480

x × 0.6 = 480

`x=480/0.6`

Perform the division: x = 800

The original number is 800