RRB Mathematics - Percentage
Exam Duration: 45 Mins Total Questions : 30
88% of 370 + 24% of 210 - ? = 118
- (a)
256
- (b)
258
- (c)
268
- (d)
358
Let 88% of 370+24% of 210-x =118.
Then, x=\(\left( \frac { 88 }{ 100 } \times 370 \right) +\left( \frac { 24 }{ 100 } \times 210 \right) -118\)
\(=325.60+50.40-118=376-118=258\)
What percent of 7.2 kg is 18 gms ?
- (a)
.025%
- (b)
.25%
- (c)
2.5%
- (d)
25%
Required percentage = \(\left( \frac { 18 }{ 7200 } \times 100 \right) \)% =\(\frac { 1 }{ 4 } \)% =0.25%
0.01 is what percent of 0.1 ?
- (a)
\(1\over100\)
- (b)
\(1\over10\)
- (c)
10
- (d)
100
Required percentage=\(\left( \frac { 0.01 }{ 0.1 } \times 100 \right) \)% =\(\left( \frac { 1 }{ 10 } \times 100 \right) \) %=10%
What percent of Rs. 2650 is Rs. 1987.50 ?
- (a)
60%
- (b)
75%
- (c)
80%
- (d)
90%
Required percentage=\(\left( \frac { 1987.50 }{ 2650 } \times 100 \right) \)% =\(\left( \frac { 19875 }{ 265 } \times \frac { 1 }{ 100 } \times 100 \right) \)%=75%
?% of 360 = 129.6
- (a)
36
- (b)
64
- (c)
72
- (d)
77
Let x% of 360=129.6. Then, \(\frac { x }{ 100 } \times 360=\frac { 1296 }{ 10 } \quad or\quad x=\left( \frac { 1296 }{ 10 } \times \frac { 100 }{ 360 } \right) =36.\)
45% of 1500 + 35% of 1700 = ?% of 3175
- (a)
30
- (b)
35
- (c)
45
- (d)
None of these
\(\sqrt{784}\) + ? = 78% of 500 :
- (a)
342
- (b)
352
- (c)
362
- (d)
372
Let \(\sqrt { 784 } +x=78\)% of 500. \(Then,\quad x=\left( \frac { 78 }{ 100 } \times 500 \right) -\sqrt { 784 } =\left( 390-28 \right) =362\)
Subtracting 40% of a number from the number, we get the result as 30. The number is:
- (a)
28
- (b)
50
- (c)
52
- (d)
70
Let the number be x. Then, 50% of x-35% of x=12
\(\Leftrightarrow \)\(\frac { 50 }{ 100 } x-\frac { 35 }{ 100 } x=12\Leftrightarrow \frac { 15 }{ 100 } x=12\Leftrightarrow \quad x=\left( \frac { 12\times 100 }{ 15 } \right) =80\)
When 15% is lost in grinding wheat, a country can export 30 lakh tons of wheat. On the other hand, if 10% is lost in grinding, it can export 40 lakh tons of wheat. The production of wheat in the country is:
- (a)
20 lakh tons
- (b)
80 lakh tons
- (c)
200 lakh tons
- (d)
800 lakh tons
Let the total production be x lakh tons. Then, 15% of x=(40-30) lakh tons \(\Leftrightarrow \) 5% of x=10 lakh tons
\(\Leftrightarrow \)x=\(\left( \frac { 10\times 100 }{ 5 } \right) =200\) lakh tons.
In an examination, 35% of the students passed and 455 failed. How many students appeared for the examination?
- (a)
490
- (b)
700
- (c)
845
- (d)
1300
Let the number of students appeared be x.
Then,65% of x=455 \(\Leftrightarrow \)\(\frac { 65 }{ 100 } x=455\Leftrightarrow x=\left( \frac { 455\times 100 }{ 65 } \right) =700\)
If p% of p is 36, then p is equal to:
- (a)
15
- (b)
60
- (c)
600
- (d)
3600
p% of p=36 \(\Leftrightarrow \) \(\left( \frac { p }{ 100 } \times p \right) =36\quad \Leftrightarrow \quad { p }^{ 2 }=3600\Leftrightarrow p=60.\)
A survey of magazine reading habits of the people living in five cities P, Q, R, S and T is summarised in a table given below. The colunm I in the table gives percentage of magazine-readers in each city who read only one magazine a week. The column II gives the total number of magazine-readers who one magazine a week. The Column II gives the total number of magazine-readers who read two or more magazine a week. Read the table and then answer these questions:
City | I | II |
P | 75 | 6000 |
Q | 80 | 3500 |
R | 60 | 3000 |
S | 55 | 2700 |
T | 25 | 4200 |
The highest number of magazine-readers in any given city is:
- (a)
17500
- (b)
18000
- (c)
24000
- (d)
30000
A survey of magazine reading habits of the people liviling in five cities P, Q, R, S and T is summarised in a table given below. The colunm I in the table gives percentage of magazine-readers in each city who read only one magazine a week. The column II given the total number of magazine-readers who one magazine a week. The Column II gives the total number of magazine-readers who read two or more magazine a week. Read the table and then answer these questions :
City | I | II |
P | 75 | 6000 |
Q | 80 | 3500 |
R | 60 | 3000 |
S | 55 | 2700 |
T | 25 | 4200 |
How many magazine-readers in city Q read only one magazine a week ?
- (a)
14000
- (b)
18000
- (c)
12500
- (d)
16500
A spider climbed 62\(1\over2\)% of the height of the pole in one hour and in the next hour it covered 12\(1\over2\)% of the remaining height. If the height of the pole is 192 m, then distance climbed in second hour is:
- (a)
3 m
- (b)
5 m
- (c)
7 m
- (d)
9 m
A salesman is allowed 5\(1\over 2\)% discount on the total sales made by him plus a bonus of \(1 \over 2\)% on the sales over Rs. 10,000. If his total earnings were 1990, then his total sales (in Rs.) were:
- (a)
30,000
- (b)
32,000
- (c)
34,000
- (d)
35,000
In a History examination, the average for the entire class was 80 marks. If 10% of the students scored 95 marks and 20% scored 90 marks, what was the average marks of the remaining students of the class?
- (a)
65.5
- (b)
72.5
- (c)
75
- (d)
85
In a city, 40% of the people are illiterate and 60% are poor. Among the rich, 10% are illiterate. What percentage of the poor population is illiterate?
- (a)
36%
- (b)
40%
- (c)
60%
- (d)
None of these
In a fraction, if numerator is increased by 40% and denominator is increased by 80%, then what fraction of the original is the new fraction?
- (a)
\(1\over2\)
- (b)
\(7\over9\)
- (c)
\(7\over18\)
- (d)
\(\)Data inadequate
The price of oil is increased by 25%. If the expenditure is not allowed to increase, the ratio between the reduction in consumption and the original consumption is
- (a)
1:3
- (b)
1:4
- (c)
1:5
- (d)
1:6
The population of a town was 1,60,000 three years ago. If it increased by 3%, 2.5% and 5% respectively in the last three years, three years, then the present population is:
- (a)
1,77,000
- (b)
1,77,366
- (c)
1,77,461
- (d)
1,77,596
The population of a town increases by 5% annually. If its population in 2001 was 1,38,915 what it was in 1998?
- (a)
1,00,000
- (b)
1,08,000
- (c)
1,10,000
- (d)
1,20,000
The population of a variety of tiny bush in an experimental field increased by 10% in the first year, increased by 8% in the second year but decreased by 10% in the third year. If the present number of business in the experimental field is 26730, then the number of bushes in the beginning was:
- (a)
25000
- (b)
27000
- (c)
28000
- (d)
24600
A building worth Rs.1,33,100 is constructed on land worth Rs.72,900. After how many years will the value of both the same if land appreciates at 10% p.a. and building depreciates at 10% p.a.?
- (a)
1\(1\over2\)
- (b)
2
- (c)
2\(1\over2\)
- (d)
3
The population of a town increases 4% annually but is decreased by emigration annually to the extent of (1/2)%. What will be the increase percent in 3 years?
- (a)
9.8
- (b)
10
- (c)
10.5
- (d)
10.8
A's salary is 50% more than B's. How much percent is B's salary less than A's?
- (a)
33%
- (b)
33\(1\over4\)%
- (c)
33\(1\over3\)%
- (d)
33\(1\over2\)%
B"s salary is less than A"s by \(\left[ \frac { 50 }{ \left( 100+50 \right) } \times 100 \right] \)% \(i.e.,\frac { 100 }{ 3 } \)% =\(33\frac { 1 }{ 3 } \)%
Peter earned 40% more money than Albert. Albert earned 20% less than Michael. Peter earned more than Michael by:
- (a)
10%
- (b)
12%
- (c)
20%
- (d)
25%
\(P=\frac { 140 }{ 100 } A\quad =\frac { 140 }{ 100 } \left( \frac { 80 }{ 100 } M \right) =\left( \frac { 140 }{ 100 } \times \frac { 80 }{ 100 } \times 100 \right) \)% of M=112% of M.
In an examination, the percentage of students qualified to the number of students appeared from school A is 70%. In school B, the number of students appeared is 20% more than the students appeared from school A and the number of students qualified from school B is 50% more than the students qualified from school A. What is the percentage of students qualified to the number of students appeared from school B?
- (a)
30%
- (b)
70%
- (c)
78.5%
- (d)
87.5%
A large watermelon weight 20 kg with 96% of its weight being water. It is allowed to stand in the sun and some of the water evaporates so that only 95% of its weight is water. Its reduced weight will be:
- (a)
16 kg
- (b)
16.5 kg
- (c)
17 kg
- (d)
18 kg
To a sugar solution of 3 litres containing 40% sugar, one litre of water is added. The percentage of sugar in the new solution is:
- (a)
13\(1\over 3\)%
- (b)
15%
- (c)
30%
- (d)
33%
Due to an increase of 30% in the price of eggs, 3 eggs less are available for Rs.7.80. The present rate of eggs per dozen is:
- (a)
Rs. 8.64
- (b)
Rs. 8.88
- (c)
Rs. 9.36
- (d)
Rs. 10.40