Question

Find the number which when decreased by 20% becomes 64.​

Answer 1

Answer:

The number is 80

Step-by-step explanation:

Let the number be x,

x - 20% of x = 64

x - 20/100 x = 64

x - x/5 = 64

5x - x/5 = 64

4x/5 = 64

4x = 64 * 5

x = 320/4

x = 80

Answer 2

Answer:

80

Step-by-step explanation:

Let the number be x

=

$\frac{x - 20 }{100 \times x } = 64 \\ \frac{x - 1x}{5} = 64 \\ \frac{5x}{5} - \frac{1x}{5} = 64 \\ \frac{4x}{5} = 64 \\ 4x = 64 \times 5 \\ x = \frac{64 \times 5}{4} \\ x = \frac{16 \times 5}{1} \\ x = 16 \times 5 \\ x = 80$