We know that for converting a percent into a decimal, we need to divide it by 100.
Hence, by division of 100, we get$52\%=\frac{52}{100}$$=0.52$
When we divide a number by 100, the decimal point shifts two places to the left.

15%  of 200
$=\frac{15}{100}\times 200$
= 15 x 2 
= 30

Method 1:
$\frac{17}{50}\times 100$
=  17 $\times$ 2 = 34 % 

Method 2:
$\frac{17}{50}\times \frac{2}{2}$   ( Since, $50\times 2=100$ )

$=\frac{34}{100}=34\%$

Number of bulbs = 200

$\%$ of green bulbs = 45

Number of green bulbs $=\frac{45}{100}\times 200$

= 45 x 2 
= 90 bulbs are green

0.1 $\%$ of 700

= $\frac{0.1}{100}\times 700$
= $\frac{1}{1000}\times 700$

= $\frac{1}{10}\times 7$

= 

= 0.7

$66\frac{2}{3}\%=\frac{200}{3}\%$

$=\frac{200}{3}\times \frac{1}{100}$

$=\frac{2}{3}$

0.75 $\times$ 100 = 75 $\%$

or, 0.75 = $\frac{75}{100}$ = 75 $\%$

1 hour = 60 minutes
$\frac{45}{60}\times 100$
= $\frac{45}{3}\times 5$
= 15 $\times$ 5
= 75$\%$

$135\%=\frac{135}{100}=\frac{27}{20}\left(\text{simplifying by 5}\right)$
$=1\frac{7}{20}$