Percentages Practice Questions – Set 1
1. In an election between two candidates, 75% of the voters cast
their votes, out of which 2% of the votes were declared invalid. A candidate
got 9261 votes which were 75% of the total valid votes. Find the total number
of votes enrolled in that election.
a)
9000
b)
15680
c)
16800
d)
17200
Answer:
C)
Explanation:
Let the number of votes enrolled be x. Then ,
Number of votes cast =75% of x. Valid votes = 98% of
(75% of x).
75% of (98% of (75%of x)) =9261.
[(75/100) * (98/100) * (75/100) * x] = 9261.
X = [(9261*100*100*100)/(75*98*75)] =16800.
2. If the numerator of a fraction be increased by 15% and its denominator
be diminished by 8%, the value of the fraction is 15/16. Find the original
fraction.
a)
5/4
b)
7/2
c)
8/3
d)
9/5
e)
None of these
Answer:
D)
Explanation:
Let the original fraction be x/y.
Then (115% of x)/(92% of y)=15/16 =>
(115x/92y)=15/16
((15/16)*(92/115))=3/4
3. In the new budget , the price of kerosene oil rose by 25%. By
how much percent must a person reduce his consumption so that his
expenditure on it does not increase ?
a)
20%
b)
27%
c)
30%
d)
40%
e)
42%
Answer:
A)
Explanation:
Reduction in consumption = [((R/(100+R))*100]%
[(25/125)*100]%=20%.
4.
During one year, the population of town increased by 5% . If the total
population is 9975 at the end of the second year , then what was the population
size in the beginning of the first year ?
a)
8000
b)
9700
c)
10000
d)
11500
e)
None of these
Answer: C)
Explanation:
Population in the beginning of the first year
= 9975/[1+(5/100)]*[1-(5/100)] =
[9975*(20/21)*(20/19)]=10000.
5. Shobha’s mathematics test had 75 problems i.e.10 arithmetic,
30 algebra and 35 geometry problems. Although she answered 70% of the
arithmetic ,40% of the algebra, and 60% of the geometry problems
correctly. she did not pass the test because she got less than 60%
of the problems right. How many more questions she would have to answer
correctly to earn 60% of the passing grade?
a)
5%
b)
13%
c)
18%
d)
20%
e)
25%
Answer:
A)
Explanation:
Number of questions attempted correctly=(70%
of 10 + 40% of 30 + 60% 0f 35)
=7 + 12+21= 45
questions to be answered correctly for 60% grade=60%
of 75 = 45
therefore required number of questions= (45-40) = 5.
6. How many kg of pure salt must be added to 30kg of 2% solution
of salt and water to increase it to 10% solution?
a)
9/4
b)
7/2
c)
8/3
d)
7/5
e)
None of these
Answer:
C)
Explanation:
Amount of salt in 30kg solution =
[(20/100)*30]kg=0.6kg
Let x kg of pure salt be added
Then , (0.6+x)/(30+x)=10/100
==> 60+100x=300+10x
==> 90x=240 ==> x=8/3.
7. Three candidates contested an election and received 1136, 7636
and 11628 votes respectively. What percentage of the total votes did the
winning candidate get?
a)
57%
b)
60%
c)
65%
d)
90%
e)
None of these
Answer:
A)
Explanation:
Total number of votes polled = (1136 + 7636 + 11628)
= 20400.
Therefore, Required percentage = (11628/20400 x 100)
% = 57%
8. 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
e)
None of these
Answer:
A)
Explanation:
Number of valid votes = 80% of 7500 = 6000.
Valid votes polled by other candidate = 45% of 6000
= (45/100 x 6000) = 2700.
9. A man sells an article at a profit of 25%. If he had bought it
at 20 % less and sold it for Rs.10.50 less, he would have gained 30%. Find the
cost price of the article?
a)
14
b)
21
c)
33
d)
35
e)
None of these
Answer:
D)
Explanation:
Let the C.P be Rs.x.
1st S.P =125% of Rs.x.= 125*x/100= 5x/4.
2nd C.P=80% of x. = 80x/100 =4x/5.
2nd S.P =130% of 4x/5. = (130/100* 4x/5) = 26x/25.
Therefore, 5x/4-26x/25 = 10.50 or x =
10.50*100/21=50.
Hence, C.P = Rs. 50.
10. A marketing manager is able to manage an average of Rs240 per week
during 40h week . But in the final week of the month, his rates are increased
by 50%. Then find out the commission the marketing manager makes in that week,
if he puts in 60h during that final week?
a) 500
b) 540
c) 520
d) 600
e) None of these
Answer:
B)
Explanation:
Average rate per hr = 240/40 = Rs6/hr
In last week, his rate per hour increases by 50%,
so in the last week, his hourly rate = Rs.6 x
(1+50%)= Rs.9
Total hour spent in final week = 60h
∴ Total commission = 60h x Rs.9/hr = Rs.540
