Percentage Questions

Let the rquired number be 'P'

According to the question,

$$\begin{gathered} 100 x P100 = 20 \\ => P = 20 x 100100 = 20 \end{gathered}$$

Hence, 100 percent of the number 20 is 20.

Now, you can also try for

20 percent of what number is 100

$$\begin{gathered} 20 x P100 = 100 \\ => P = 100 x 10020 = 500 \\ => P = 500 \end{gathered}$$

Hence, 20 percent of the number 500 is 100.

Let total number of votes enrolled = x
No. of voted cast = 70% of x = 0.7x
Valid votes = 98% of 0.7x
⇒ 60% of total valid votes = 7203 = 60% of 98% of 0.7x
⇒ 0.6 X 0.98 X 0.7x = 7203
⇒ x = 7203 / (0.6 X 0.98 X 0.7)
⇒ x = 17500

1st day the girl read = 40%

2nd day she read = 34 %

Remaining percentage of book = 100% - (40% +34%) = 26%

But given last two days she read equal number of pages

=> Each day she read 26%/2 = 13%

Last day she read 52 pages = 13%

13% = 52

1% = 4

=> 100% = 400

Total pages in the book is 400.

75% of 450 + ? % of 560 = 600 

$$\begin{gathered} 75 x 450100 + ? x 560100 = 600 \\ 75 x 92 + 28p5 = 600 \\ 75x9x5 + 56p10 = 600 \\ 3375 + 56p = 6000 \\ 56p = 2625 \\ p = 46.875 \end{gathered}$$

Hence, in the given question ? = 46.875

74.99% of 1299 + 8.98% of 1899 = ? 

$$\begin{gathered} ? = 75 x 1400100 + 9 x 1800100 \\ ? = 1050 + 162 \\ ? = 1212. \end{gathered}$$

This can be solved as

$$\begin{gathered} 20 1 - 4202 = 20 1 - 152 \\ = 20452 \\ = 20 1625 \\ = 645 \\ = 12.8 \end{gathered}$$

Here 85 of 352 => 85 is what percent in 352

Let p% of 352 is 85

Percentage(%) is generally calculated in the total of 100.

=> p x 352/100  = 85

=> p = 8500/352  = 24.14%

Hence, 85 is 24.14% of 352.