Question

0.5% of what number is 5?

Answer 1

Let us call the unknown number "unknown number". Then we know that 0.5% of the number is 5, in other words

$\frac{0.5}{100}\times unknown\text{ number = 5}$

multiplying both sides by 100 gives

$100\times\frac{0.5}{100}\times unknown\text{ number = 5}\times100$$0.5\times unknown\text{ number = }500$

and then dividing both sides by 0.5 gives

$\frac{1}{0.5}\times0.5\times unknown\text{ number = }\frac{500}{0.5}$$unknown\text{ number = }\frac{500}{0.5}$$unknown\text{ number = }1000.$

Hence, 0.5% of 1000 is 5.