Given,
60% of work whose age is 30 above
1350 males work whose age is 30 above.
75% of workers are male whose age are 30 above.
25% of female workers whose ages are 30 above.
Number of female work whoes age 30 above
= $$\frac{{1350}}{{75}} \times 25 = 450$$
total number of work whoes age are 30 above = 1350 + 450 = 1800(60% of work)
Total number of work = $$\frac{{1800}}{{60}} \times 100 = 3000$$

Required percentage :
$$\eqalign{ & = \left( {\frac{{1.14}}{{1.9}} \times 100} \right)\% \cr & = \left( {\frac{{114}}{{190}} \times 100} \right)\% \cr & = 60\% \cr} $$

x = 63% of y
⇒ x = $$\frac{63y}{100}$$
⇒ y = $$\frac{100x}{63}$$
∴ Required percentage :
$$\eqalign{ & = \left( {\frac{{{y^2}}}{{{x^2}}} \times 100} \right)\% \cr & = \left[ {{{\left( {\frac{{100x}}{{63}}} \right)}^2} \times \frac{1}{{{x^2}}} \times 100} \right]\% \cr & = \left( {\frac{{10000}}{{3969}} \times 100} \right)\% \cr & = 251.96\% \approx 250\% \cr} $$

Let salary = 100 units
Savings = 20%
Savings = 100 × $$\frac{20}{100}$$ = 20 units
Expenditure = (100 - 20) = 80 units
According to question,
80 units = Rs. 6000
1 unit     = Rs. 75
Savings = 75 × 20 = Rs. 1500

Total number of students :
= 1100 + 700
= 1800
Number of students passed :
= (42% of 1100 + 30% of 700)
= (462 + 210)
= 672
Number of failures :
= 1800 - 672
= 1128
∴ Percentage failure :
= $$\left( {\frac{{1128}}{{1800}} \times 100} \right)\% $$
= $$62\frac{2}{3}\% $$

Increase in height = 15% = $$\frac{3}{20}$$
Decrease in base radius = 10% = $$\frac{1}{10}$$

Let number is = 100x
Now after 15% of increase = 100x + 15% of 100x = 115x
Now 25% decrease = 115x - 25% of 115x = 115x - 28.75x = 86.25x
Actual decreased = 100x - 86.25x = 13.75x
According to question,
13.75x = 22
x = $$\frac{22}{13.75}$$
100x = $$\frac{22}{13.75}$$   × 100 = 160
∴ Original number = 160

Required % decrements :
$$\eqalign{ & = \frac{{{x^2}}}{{100}}\% \cr & = \frac{{{{\left( {25} \right)}^2}}}{{100}} \cr & = 6\frac{1}{4}\% \cr} $$

Let sum invested at 5% be Rs. x and that invested at 3% be Rs. (9600 - x)
Then, 5% of x = 3% of (9600 - x)
⇒ 5x = 3 (9600 - x)
⇒ 8x = 28800
⇒ x = 3600
Hence, total income :
= 5% of x + 3% of (9600 - x)
= Rs. (5% of 3600 + 3% of 6000)
= Rs. (180 + 180)
= Rs. 360

Let ir marks be (x + 9) and x
Then,
$$\eqalign{ & x + 9 = \frac{{56}}{{100}}\left( {x + 9 + x} \right) \cr & \Rightarrow 25\left( {x + 9} \right) = 14\left( {2x + 9} \right) \cr & \Rightarrow 3x = 99 \cr & \Rightarrow x = 33 \cr} $$
So, ir marks are 42 and 33