Question

(i) Find the number whose $6\frac{1}{4}\%$ is 5.
(ii) Find 0.8% of 45.

Answer 1

(i) Let x be the required number.
Then, $6\frac{1}{4}\%$ of x = 5
⇒ $\frac{25}{4}\%$ of x = 5
⇒ $\left(\frac{25}{4\times 100}\times x\right)=25$
⇒$\left(\frac{x}{16}\right)=5$
∴ x = (5 $\times$ 16) = 80
Hence, the required number is 80.

(i) 0.8% of 45 =$\left(\frac{0.8}{100}\times 45\right)$
=$\left(\frac{8}{10\times 100}\times 45\right)$
= $\left(\frac{72}{200}\right)=\left(\frac{36}{100}\right)=0.36$
Hence, 0.8% of 45 is 0.36.