Aptitude - Percentage
1.
40% of ? = 240
Answer
Let 40% of x = 240. Then, 40100 x x = 240
⇒ x = 240 x 10040 = 600
Answer :
Option DExplanation :
Let 40% of x = 240. Then, 40100 x x = 240
⇒ x = 240 x 10040 = 600
2.
x% of x is the same as 10% of :
Answer
Let x% of x = 10% of y. Then,
x100 x x = 10100 x y ⇒ y10 = x2100 ⇒ y = x210
Answer :
Option BExplanation :
Let x% of x = 10% of y. Then,
x100 x x = 10100 x y ⇒ y10 = x2100 ⇒ y = x210
3.
If the average of a number, its 75% and its 25% is 240, then the number is :
Answer
Let the number be x. Then,
13
x + 75100 of x + 25100 of x 
= 240
⇒ x + 3x4 + x4 = 720 ⇒ (4x + 3x + x) = 2880
⇒ 8x = 2880 ⇒ x = 360
Hence, the number is 360
Answer :
Option CExplanation :
Let the number be x. Then,
13
x + 75100 of x + 25100 of x = 240⇒ x + 3x4 + x4 = 720 ⇒ (4x + 3x + x) = 2880
⇒ 8x = 2880 ⇒ x = 360
Hence, the number is 360
4.
Hari's income is 25% more than Madhu's income. Madhu's income is less than Hari's income by :
Answer
Let Madhu's income = Rs. 100. Then, Hari's income = Rs. 125
Required % = 25125 x 100 % = 20%
Answer :
Option BExplanation :
Let Madhu's income = Rs. 100. Then, Hari's income = Rs. 125
Required % =
25125 x 100 % = 20% 5.
In an examination, 65% of the total examinees passes. If the number of failures is 420, the total number of examinees is :
Answer
Percentage of failures = (100 − 65)% = 35%
Let the total number of examinees be x. Then,
35% of x = 420 ⇒ 35100 x x = 420
⇒ x = 420 x 10035 = 1200
Answer :
Option BExplanation :
Percentage of failures = (100 − 65)% = 35%
Let the total number of examinees be x. Then,
35% of x = 420 ⇒ 35100 x x = 420
⇒ x =
420 x 10035 = 1200 Jump to page number :