ExamAdept

In an election between two candidates, one got 55% of the total valid votes, 20% of the votes were invalid. If the total number of votes was 7500, the number of valid votes that the other candidate got, was:

A:

2700

B:

2900

C:

3000

D:

3100

Answer: A

Number of valid votes = 80% of 7500 = 6000.

Valid votes polled by other candidate = 45% of 6000

=		45	x 6000		= 2700.
		100

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A student multiplied a number by	3	instead of	5	.
	5		3

What is the percentage error in the calculation?

A:

34%

B:

44%

C:

54%

D:

64%

Answer: D

Let the number be x.

Then, error =	5	x -	3	x =	16	x.
	3		5		15

Error% =		16x	x	3	x 100	% = 64%.
		15		5x

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Two numbers A and B are such that the sum of 5% of A and 4% of B is two-third of the sum of 6% of A and 8% of B. Find the ratio of A : B.

A:

2 : 3

B:

1 : 1

C:

3 : 4

D:

4 : 3

Answer: D

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

	5	A +	4	B	=	2		6	A +	8	B
	100		100			3		100		100

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

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

	1	A =	1	B
	100		75

A	=	100	=	4	.
B		75		3

Required ratio = 4 : 3

Video Explanation: YouTube Video

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In a certain school, 20% of students are below 8 years of age. The number of students above 8 years of age is of the number of students of 8 years of age which is 48. What is the total number of students in the school?

A:

72

B:

80

C:

120

D:

150

Answer: E

Let the number of students be x. Then,

Number of students above 8 years of age = (100 - 20)% of x = 80% of x.

80% of x = 48 +	2	of 48
	3

	80	x = 80
	100

x = 100.

Video Explanation: https://youtu.be/yPfocU6DA2M

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If 20% of a = b, then b% of 20 is the same as:

A:

4% of a

B:

5% of a

C:

20% of a

D:

None of these

Answer: A

20% of a = b	20	a = b.
	100

b% of 20 =		b	x 20		=		20	a x	1	x 20		=	4	a = 4% of a.
		100					100		100				100

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Questions for: Percentage