Aptitude :: Percentage

Practice :: Percentage - General Questions
Percentage - General Questions

Page Title 6. 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.
4 : 7
7 : 3
4 : 3
4 : 5
Answer: option C

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

⟹ (1/100)A = (1/75)B

A/B = 100/75 = 4/3

∵ Required ratio = 4 : 3



7. In an election between two candidates Ramesh and Suresh, 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:
2000
1700
2300
2700
Answer: option D

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

∵ Valid votes polled by other candidate = 45% of 6000

= (45/100 x 6000) = 2700



8. A student multiplied a number by 3/5 instead of 5/3
What is the percentage error in the calculation?
57%
64%
42%
55%
Answer: option B

Let the number be X.

Then, error = (5/3)X - (3/5)X = (16/15)X

∵ Error% = (16X/15 x 3/5X x 100)% = 64%



9. If 20% of A = B, then B% of 20 is the same as:
4% of A
7% of A
9% of A
5% of A
Answer: option A

20% of A = B ⟹ (20/100)A = B

∵ B% of 20 = (B/100 x 20) = (20/100)A x 1/100 x 20

⟹ (4/100)A = 4% of A



10. Three candidates contested an election and got 1136, 7636 and 11628 votes respectively. What percentage of the total votes did the winning candidate get?
61%
43%
57%
54%
Answer: option C

Total number of votes polled = (1136 + 7636 + 11628) = 20400.

∵ Required percentage = (11628/20400 x 100)% = 57%




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