If the side of a square is increased by 30%, its area is increased by?

Let the total number of students be 100
Then, n(A ? B) = n(A) + n(B) - n(A ? B) = (72 + 44 - 100)% = 16%
Now,16% of N = 40
? (16 x N) / 100 = 40
? N = (100 x 40) / 16 = 250

Suppose boys = 3N and girls = 2N
Not adults = (80% of 3N) + (75% of 2N) = (12N/5 + 3N/2) = 39N/10
? Required percentage = (39N/10 / 1/5N) x 100 % = 78%

? Milk = 90% 0f 40 = 36 litres and water = 4 litres.
Let L litre water to be added in order to make 20% water in new mixture.
? {(4 + L) / (40 + L)} x 100 = 20
? 20 x (40 + L) = 100 x (4 + L)
? 80 x L = 400
? L = 5 litres .

Let the original fraction be p/q
Now, (120% of p) / (90% of q) = 16 / 21
? 4p / 3q = 16/21
? p / q = (16/21) x (3/4) = 4 / 7

Let original price = Rs. 100
Reduced price = Rs. 75
Increase on Rs. 75 = Rs. 25
Increase on Rs. 100 = (25 x 100)/75 % = 33¹/₃ %

Let radius of circle = 100 m
New radius = 101 m
original area = [? x (100)² ]m²
New area = [? x (101)² ]m²
Increase% = [? x {(101)² - (100)²} / { ? x (100)²} ] x 100 %
= 201 / 100% = 2.01%

Let length of square = 100 m and breadth of square = 100 m
Area = (100 x 100) m² = 10000 m²
New length = 130 m and breadth = 120 m

New area of rectangle = (130 x 120) m² = 15600 m²
Increase % = (5600 / 10000) x 100 % = 56%

Let length of a rectangle = 100 m,
Breadth = 100 m
New length = 160 m,
New breadth = B meters
Then, 160 x B = 100 x 100
? B = (100 x 100) / 160 = 125/2
Decrease in breadth = (100 - 125/2)% = 37¹/₂%

Consumption Decreases = (common %)²/100
= 225/100
= 2.25%.

Required number = 800 x (1 + 15/100)²
= 800 x (23/20) x (23/20)
= 1058