Question

Match the correct pairs.

• A. 12.5
• B. 99
• C. 25
• D. 46

Answer 1

(i) 40 increased by 15 %
$\Rightarrow$ 40 + 15% of 40
$\Rightarrow 40+\frac{15}{100}\times 40=40+6=46$
$\therefore$ when 40 is increased by 15 % , the result is 46

(ii) 110 increased by 10 %
$\Rightarrow$ 110 - 10% of 110
$\Rightarrow 110-\frac{10}{100}\times 110=110-11=99$
$\therefore$ when 110 is decreased by 10 %, the result is 99

(iii) Assume we have to find x
$\Rightarrow$$\frac{9}{8}=(100+x)\%$

$\Rightarrow$$\frac{9}{8}=\frac{100+x}{100}$

$\Rightarrow$$\frac{9\times 100}{8}=100+x$

$\Rightarrow 112.5=100+x$
$\Rightarrow x=112.5-100=12.5$

(iv) Assume we have to find x
$\Rightarrow$$\frac{6}{8}=(100-x)\%$

$\Rightarrow$$\frac{6}{8}=\frac{100-x}{100}$

$\Rightarrow$$\frac{6\times 100}{8}=100-x$

$\Rightarrow 75=100-x$
$\Rightarrow x=100-75=25$