If one needs to score 34% to pass a test, the pass marks out of 40 would be:

 

80x900/100 + 256 x 4 x ? = 1331 - 99

720 + 1024 x ? = 1232

? = 1232 - 720/1024

? = 512/1024 = 0.5

? = 0.5 

what is 70 of 50 means 70% of 50

$$\begin{gathered} ⇒70 x 50100 \\ = 7 x 5 \\ = 35 \end{gathered}$$

Hence, 70 of 50 is 35.

Let total amount = Rs. P

Total expenditure = (23 + 33 + 19 + 16)% of P = 91%ofP

Remaining money = (100 - 91)% of P = 9% of P

But given in the question that,

9% of P = 504

9p/100 = 504

=> P = 50400/9

=> P = Rs. 5600

Required money spent on Food & Insurance = 23 + 33 %

= 56% of 5600

= 56 x 5600/100 = 56 x 56 = Rs. 3136

Total number of female members = 115

Let the number of males = x

Number of females = y

=> x + y = 115  ......(1)

According to the given data,

x + y(0.50) = 69 ......(2)

From (1) & (2), we get

0.5y = 46

=> y = 46 x 2 = 92

=> x = 115 - 92 = 23

Hence, required number of gentlemen in the family = x = 23.

Given 30% of 500

$$\begin{gathered} = 30100 x 500 \\ = 30 x 5 \\ = 150 \end{gathered}$$

Hence, 30% of Rs. 500 = Rs. 150.

$$\begin{gathered} Given 3.2% of 500 × 2. 4% of ? = 312 \\ Then, \\ 3.2 x 500100 x 2.4 x ?100 = 312 \\ 16 x 2.4x?100 = 312 \\ 9.6 x ?25 = 312 \\ 9.6 x ? = 7800 \\ ? = 78009.6 \\ ? = 812.5 \end{gathered}$$

1/2 as a percentage means

1/2 = 0.5 in decimal

Now, in percentage means 0.5 x 100% = 50%.

Let the required number be 'p'

36 of what number is 18 implies 36% of p = 18

=> 36 x p/100 = 18

=> p = 1800/36

=> p = 50.

Hence, 36% of 50 is 18.