71. The height of two right circular cones are in the ratio 1:2 and their perimeters of their bases are in the ratio 3:4, the ratio of their volume is_________?
A. 3:8
B. 9:16
C. 9:32
D. 9:64
✅ The correct answer is option C. 9:32.
Mathematics
Practice the latest Mathematics MCQs with answers and explanations to excel in exams, interviews, and job tests. Our collection covers algebra, calculus, geometry, trigonometry, statistics, probability, arithmetic, matrices, and differential equations. These Mathematics multiple-choice questions are designed for students, competitive exam aspirants, and professionals preparing for NTS, PPSC, FPSC, CSS, PMS, university entry tests, and recruitment assessments. Strengthen your problem-solving skills, improve accuracy, and boost your exam performance with our updated Mathematics MCQs.
72. The sum and the product of the roots of the quadratic equation x(power 2) + 20x + 3 = 0 are?
A. 10, 3
B. -10, 3
C. -20, 3
D. -10, -3
✅ The correct answer is option C. -20, 3.
Sum of the roots and the product of the roots are -20 and 3 respectively.
Sum of the roots and the product of the roots are -20 and 3 respectively.
73. A sum of Rs. 725 is lent in the beginning of a year at a certain rate of interest. After 8 months, a sum of Rs. 362.50 more is lent but at the rate twice the former. At the end of the year, Rs. 33.50 is earned as interest from both the loans. What was the original rate of interest?
A. 3.46%
B. 4.5%
C. 5%
D. 6%
✅ The correct answer is option A. 3.46%.
Note: Here, original rate is for 1 year(s); the new rate is for only 4 months i.e.1/3 year(s).
Note: Here, original rate is for 1 year(s); the new rate is for only 4 months i.e.1/3 year(s).
74. A and B invests Rs.8000 and Rs.9000 in a business. After 4 months, A withdraws half of his capital and 2 months later, B withdraws one-third of his capital. In what ratio should they share the profits at the end of the year?
A. 20:23
B. 34:43
C. 32:45
D. 37:45
✅ The correct answer is option C. 32:45.
75. Two pipes can fill a tank in 20 and 24 minutes respectively and a waste pipe can empty 3 gallons per minute. All the three pipes working together can fill the tank in 15 minutes. The capacity of the tank is?
A. 60 gallons
B. 100 gallons
C. 120 gallons
D. 180 gallons
✅ The correct answer is option C. 120 gallons.
76. Twenty women can do a work in sixteen days. Sixteen men can complete the same work in fifteen days. What is the ratio between the capacity of a man and a woman ?
A. 3 : 4
B. 4 : 3
C. 5 : 3
D. Data inadequate
✅ The correct answer is option B. 4 : 3.
77. The cost of 2 chairs and 3 tables is Rs.1300. The cost of 3 chairs and 2 tables is Rs.1200. The cost of each table is more than that of each chair by__________?
A. Rs.70
B. Rs.75
C. Rs.50
D. Rs.60
✅ The correct answer is option E. None of these.
78. A tank can be filled by a pipe in 20 min. and by another pipe in 60 min. Both the pipes are kept open for 10 min. and then the first pipe is shut off. After this, the tank will be completely filled in__________?
A. 10 min
B. 20 min
C. 30 min
D. 40 min
✅ The correct answer is option B. 20 min.
79. The number obtained by interchanging the two digits of a two-digit number is less than the original number by 45. If the sum of the two digits of the number so obtained is 13, then what is the original number?
A. 49
B. 94
C. 83
D. Either (a) or (b)
✅ The correct answer is option B. 94.
80. In what proportion must water be added to spirit to gain 20% by selling it at the cost price?
A. 2:5
B. 1:5
C. 3:5
D. 4:5
✅ The correct answer is option B. 1:5.