561. The difference between a number and its two-fifth is 510. What is 10% of that number?
A. 12.75
B. 85
C. 204
D. None of these

Explanation:
Let the number be x. Then,
x – 2/5 x = 510
x = (510 * 5)/3 = 850
10% of 850 = 85.

562. Two-fifth of one-third of three-seventh of a number is 15. What is 40% of that number?
A. 72
B. 84
C. 136
D. 140
E. None of these

Explanation:
Let the number be x. Then,
2/5 of 1/3 of 3/7 of
x = 15 => x = (15 * 5/3 * 3 * 5/2) = 525/2
40% of 525/2 = (40/100 * 525/2) = 105

563. If 20% of a number, then 120% of that number will be_________?
A. 20
B. 120
C. 360
D. 720

Explanation:
Let the number x. Then,
20% of x = 120
x = (120 * 100)/20 = 600
120% of x = (120/100 * 600) = 720.

564. 45% of 750 – 25% of 480 =__________?
A. 216
B. 217.50
C. 236.50
D. 245

Explanation:
Given expression = (45/100 * 750) – (25/100 * 480) = (337.50 – 120) = 217.50

565. 3.5 can be expressed in terms of percentage as?
A. 0.35%
B. 3.5%
C. 35%
D. 350%

Explanation:
3.5 = 35/10 = (35/10 * 100) = 350%

566. The ratio of the prices of three articles X, Y and Z is 8 : 5 : 3. If the prices of X , Y and Z are increased by 25%, 20% and 33 1/3% respectively, then what would be the ratio of the new prices of X, Y and Z?
A. 5 : 3 : 1
B. 5 : 3 : 2
C. 10 : 7 : 4
D. 10 : 8 : 5
E. None of these

Explanation:
Let the prices of X, Y and Z be 8k, 5k and 3k respectively.
After increase
Price of X = 8k * 125/100 = 10k
Price of Y = 5k * 120/100 = 6k
Price of Z = 3k * (133 1/3)/100 = 4k
Required ratio = 10k : 6k : 4k = 5 : 3 : 2

567. Two tests had the same maximum mark. The pass percentages in the first and the second test were 40% and 45% respectively. A candidate scored 216 marks in the second test and failed by 36 marks in that test. Find the pass mark in the first test?
A. 136
B. 128
C. 164
D. 214
E. None of these

Explanation:
Let the maximum mark in each test be M.
The candidate failed by 36 marks in the second test.
pass mark in the second test = 216 + 36 = 252
45/100 M = 252
Pass mark in the first test = 40/100 M = 40/45 * 252 = 224.

568. In an election between two candidates A and B, the number of valid votes received by A exceeds those received by B by 15% of the total number of votes polled. If 20% of the votes polled were invalid and a total of 8720 votes were polled, then how many valid votes did B get?
A. 2160
B. 2420
C. 2834
D. 3150
E. None of these

Explanation:
Let the total number of votes polled in the election be 100k.
Number of valid votes = 100k – 20% (100k) = 80k
Let the number of votes polled in favour of A and B be a and b respectively.
a – b = 15% (100k) => a = b + 15k
=> a + b = b + 15k + b
Now, 2b + 15k = 80k and hence b = 32.5k
It is given that 100k = 8720
32.5k = 32.5k/100k * 8720 = 2834
The number of valid votes polled in favor of B is 2834.

569. In an office, totally there are 6400 employees and 65% of the total employees are males. 25% of the males in the office are at-least 50 years old. Find the number of males aged below 50 years?
A. 1040
B. 2080
C. 3120
D. 4160
E. None of these

Explanation:
Number of male employees = 6400 * 65/100 = 4160
Required number of male employees who are less than 50 years old = 4160 * (100 – 25)%
= 4160 * 75/100 = 3120.

570. The monthly incomes of A and B are in the ratio 5 : 2. B’s monthly income is 12% more than C’s monthly income. If C’s monthly income is Rs. 15000, then find the annual income of A?
A. Rs. 420000
B. Rs. 180000
C. Rs. 201600
D. Rs. 504000
E. None of these

Explanation:
B’s monthly income = 15000 * 112/100 = Rs. 16800
B’s monthly income = 2 parts —-> Rs. 16800
A’s monthly income = 5 parts = 5/2 * 16800 = Rs. 42000
A’s annual income = Rs. 42000 * 12 = Rs. 504000