Percentage problems
- 1. Rajesh solved 80 percent of the questions in an examination correctly, out of 41 questions solved by Rajesh 37 questions are correct and of the remaining questions out of 8 questions, 5 questions have been solved by Rajesh correctly then find the total number of question asked in the examination?
Options- A. 75
- B. 65
- C. 60
- D. Can't be determined Discuss
Correct Answer: 65
Explanation:
Suppose there are 8y questions were asked apart from the 41 question.Then
37 + 5y/41 + 8y = 80% = 4/5
? 185 + 25y = 164 + 32y
? 7y = 21
? y = 3
? Total no. of questions = 41 + 8 x 3 = 65.
- 2. In a class of 60 children 30% children can speak only English, 20% Hindi and English both and the rest of the children can speak only Hindi. How many children can speak Hindi?
Options- A. 42
- B. 36
- C. 30
- D. 48 Discuss
Correct Answer: 42
Explanation:
Number of student who speak only English =30% of 60 = 18
Number of student who speak Hindi and English =20% of 60 =12
?Number of student who speak only Hindi = (60 - 30) = 30
?Number of student who speak Hindi = 30 + 12 = 42
- 3. The ratio of males and females in a city is 7:8 and the percentage of children among males and females is 25% and 20% respectively.If the number of adult females in the city is 156800, what is the total population?
Options- A. 245000
- B. 367500
- C. 196000
- D. 171500 Discuss
Correct Answer: 367500
Explanation:
Number of females = 156800 x 100/80 = 196000
? Number of males = 7/8 x 196000 = 171500
Total population = 196000 + 171500 = 367500
- 4. The ratio of the number of student appearing for examination in the year 1998 in the states A, B and C was 3 : 5 : 6. Next year if the number of students in these states increase by 20%, 10% and 20% respectively, the ratio in states A and C would be 1 : 2. What was the number of students who appeared for the examination in the state A in 1999?
Options- A. 7200
- B. 6000
- C. 7500
- D. Data inadequate Discuss
Correct Answer: Data inadequate
Explanation:
Let the number of students appearing for examination in the year 1998 in the states A, B and C be 3N, 5N,and 6N respectively.
According to the question, {(3N x 120)/100} / {(6N x 110)/100} = 1/2
Its true for every N so, The data is inadequate.
- 5. After spending 40% in machinery, 25% in building,15% in raw material and 5% on furniture. hari lal has a balance of Rs. 1305. The money with him was?
Options- A. Rs. 6500
- B. Rs. 7225
- C. Rs. 8700
- D. Rs. 1390 Discuss
Correct Answer: Rs. 8700
Explanation:
Let the Hari Lal was having R rupees in beginning.
? R - [40% of R + 25% of R + 15% of R + 5% of R] = 1305
? R - 85% of R = 1305
? 15% of R = 1305
? R = (1305 x 100)/15 = 8700
- 6. In mathematics exam. a student scored 30% marks in the first paper out of a total of 180. How much should he score in second paper out of a total of 150, If he is to get an overall average of at least 50%?
Options- A. 74%
- B. 76%
- C. 70%
- D. 80% Discuss
Correct Answer: 74%
Explanation:
? 30% of 180 + N% of 150 = 50% of (180 + 150)
? 54 + (N x 150)/100 = 165
? 3N/2 = 111
? N = (111 x 2) / 3 =74
- 7. In a examination it is required to get 36% of maximum marks to pass. A student got 113 marks and declared failed by 85 marks. The maximum marks are?
Options- A. 500
- B. 550
- C. 640
- D. 1008 Discuss
Correct Answer: 550
Explanation:
? 36% of N = (113 + 85)
? N = (100 x 198) / 36 = 550
- 8. From the salary of an officer 10% deducted as house rent,15% of the rest he spends on children's eduction and 10% of the balance, he spends on clothes. After this expenditure he is left with Rs. 1377. His salary is?
Options- A. Rs. 2000
- B. Rs. 2040
- C. Rs. 2100
- D. Rs. 2200 Discuss
Correct Answer: Rs. 2000
Explanation:
Suppose that his salary = Rs. 100
House Rent = Rs.10
so, Balance = Rs. 90
Expenditure on education = Rs. (15 x 90) / 100= Rs.13.50
Balance =Rs.76.50
Expenditure on clothes = Rs.(10 x 76.50) / 100 = Rs. 7.65
Balance now = Rs.68.85
If balance is Rs. 68.85, salary =Rs. 100
If balance is Rs. 1377, salary = Rs.(100/68.85) x 1377 = Rs. 2000
- 9. The price of cooking oil has increased by 25%. The percentage of reduction that a family should effect in the use of cooking oil so as not to increased the expenditure on this account is?
Options- A. 15%
- B. 20%
- C. 25%
- D. 30% Discuss
Correct Answer: 20%
Explanation:
Reduction in consumption = { m / (100 + m)} x 100%
= (25/125) x 100%
= 20%
- 10. Out of a total 85 children playing badminton or table tannins or both,total number of girl in the group is 70% of boys in the group. The number of boys playing only badminton is 50% of the number of boys and the total number of boys playing badminton is 60% of the total number of boys. The number of children playing only table tennis is 40% of the total numbers of children and a total numbers of children and a total 12 children play badminton and table tennis both. What is the number of girls playing only badminton?
Options- A. 16
- B. 14
- C. 17
- D. Data inadequate Discuss
Correct Answer: 14
Explanation:
Let the number of boys = x
then x + 7x/10 = 85
? x = 50
? No. of girls = 85 - 50 = 35
(i) Number of boys playing only badminton =50% of boys
= 50/100 x 50 = 25
(ii) Number of children playing only table tennis
= 40% of total no. of children
= 40/100 x 85 = 34
(iii) Total no. of children playing both badminton and table tennis = 12
Hence, number of girls playing only badminton = 85 - (25 + 34 + 12)
= 85 - 71 = 14.
More in Aptitude:
Programming
Copyright ©CuriousTab. All rights reserved.