Answer: 4 : 3

Explanation:
5% of A + 4% of B = 2/3  (6% of A + 8% of B)

5/100  A + 4/100  B = 2/3   (6/100  A + 8/100 B)  

1/20  A + 1/25  B = 1/25  A + 4/75  B
   
1/20 - 1/25   A = 4/75 - 1/25   B
  

Answer: 4.8% 

Explanation:
Let there be x litres of sugar in solution.
x / 6 × 100 = 4
x = 24/100 = 0.24 lit
Percentage of sugar in remaining solution = 0.24 / 5 × 100 = 4.8%

Answer: 80%

Explanation:
Let D get x%. Then C gets 0.8x%, B gets 1.25(0.8)x% and A gets (0.9 × 1.25 × 0.8 × x%) i.e. 0.9x%
360/500 × 100 = 0.9x
x = 80%

Answer: 1000000

Explanation:
Explanation:
Population after 2 years = Present Population ( 1 – r1/100) (1 – r2/100)
P(1 – 5/100) (1 – 5/100) = 902500
P = 1000000

Answer: 50

Explanation:
Let the maximum marks be x. 20 / 100 x + 10 = 42 / 100 x -1
11 = 22 / 100 x
x = 50 marks.

Answer: 20

Explanation:
Percentage increase in consumption = (x / 100 – x) ×100
= 10 / 90 × 100 = 11 1/9%
Quantity of sugar that can be bought for new price =
18 + [((100 / 9) / 100) × 18] = 18 + 2 = 20 quintals

Answer: 0.25%

Explanation:
Let the sides of the rectangle be l1 and b1.
Initial area of the rectangle , A1 = l1b1
Find the area of the rectangle, A2 = (0.95 l1)(1.05)b1 = 0.9975 l1b1.
Change in the area = l1b1 – 0.9975 l1b1 = 0.0025 l1b1
Percentage change = (0.0025 l1b1) / l1b1 × 100 = 0.25%

Answer: 25% 

Explanation:
 Let B’s salary is Rs. 100. A’s salary is 20% below than B’s salary. Hence, salary of A = Rs. 80. B’s salary is (20 / 80 × 100) percentage above A’s salary, i.e 25% above A’s salary.

Answer: 2030

Explanation:
Let the total number of students be x. If 60% are boys then 40% are girls. 40/100 x =812
x = (812 × 100) / 40 = 2030.

Answer: 38.8% 

Explanation:
Let marked Price = Rs. 100
1st discount = 100 × 20 /100 = Rs. 20
2nd discount = (100 – 20) × 15 / 100 = 80 × 15 /100 = Rs. 12
3rd discount = (80 – 12) × 10/100 = 68/10 = Rs. 6.8
Single discount = Sum of all the discounts = 20 + 12 + 6.8 = 38.8%