All Free Mathematics MCQs with Answers
Every Mathematics question in the bank, across all chapters, each with the correct answer and a written explanation. Free and unlimited, with no account needed.
1,551 questions · page 52 of 78
- A. 90730
- B. 90725
- C. 90715
- D. 90720
Explanation: The LCM of 32, 36, 40, 42 and 48 is 2^5 x 3^2 x 5 x 7 = 10080. The greatest five-digit multiple is 10080 x 9 = 90720, because 10080 x 10 =…
Correct answer: 90720- A. (36,60)
- B. (12,180)
- C. (96,25)
- D. (72,30)
Explanation: For 36 and 60, the product is 36 x 60 = 2160 and their HCF is 12, since both divide by 12 but have no larger common divisor.
Correct answer: (36,60)- A. 246 seconds
- B. 242 seconds
- C. 240 seconds
- D. 243 seconds
Explanation: The bells toll together after the LCM of their intervals: LCM(8, 10, 12, 16) = 2^4 x 3 x 5 = 240 seconds.
Correct answer: 240 seconds- A. 71
- B. 70
- C. 69
- D. 68
Explanation: The LCM of 8, 12 and 18 is 2^3 x 3^2 = 72. Therefore the least intended number is 72 - 3 = 69, because adding 3 gives 72, which is…
Correct answer: 69- A. 982
- B. 893
- C. 1024
- D. 995
Explanation: Test the congruences for 995: 995 = 16 x 62 + 3, 995 = 18 x 55 + 5, and 995 = 21 x 47 + 8.
Correct answer: 995- A. 2040
- B. 2010
- C. 135
- D. 150
Explanation: For two positive integers, product = HCF x LCM. Therefore LCM = 2025 / 15 = 135.
Correct answer: 135- A. 34
- B. 17
- C. 85
- D. 204
Explanation: Using the Euclidean algorithm, gcd(204, 1190) = gcd(204, 170) = 34, and gcd(34, 1445) = 17. Therefore the HCF of all three numbers is 17.
Correct answer: 17- A. 1
- B. 2
- C. 3
- D. 4
Explanation: The common factors are found successively: gcd(12, 16) = 4, gcd(4, 18) = 2, and gcd(2, 24) = 2. Thus the HCF is 2.
Correct answer: 2- A. 2/47
- B. 3/47
- C. 1/48
- D. 5/48
Explanation: For fractions, HCF = HCF of the numerators divided by LCM of the denominators. Thus HCF(3, 5, 7) / LCM(16, 12, 8) = 1/48.
Correct answer: 1/48- A. 10/7
- B. 10
- C. 10/11
- D. 11/10
Explanation: For positive fractions, LCM = LCM of the numerators divided by HCF of the denominators.
Correct answer: 10- A. 10670
- B. 106470
- C. 104670
- D. 107470
Explanation: Factor the numbers: 455 = 5 x 7 x 13, 117 = 3^2 x 13, and 338 = 2 x 13^2. Their LCM is 2 x 3^2 x 5 x 7 x 13^2 = 106470.
Correct answer: 106470- A. 1305
- B. 435
- C. 875
- D. 48
Explanation: Since 87 = 3 x 29 and 145 = 5 x 29, their HCF is 29 and their LCM is 3 x 5 x 29 = 435. Equivalently, 87 x 145 / 29 = 435.
Correct answer: 435- A. 85
- B. 89
- C. 54
- D. 91Election Officer Mcqs
Explanation: Write 18 = 2 x 3^2 and 27 = 3^3. Taking the highest power of each prime gives LCM = 2 x 3^3 = 54.
Correct answer: 54- A. 46
- B. 138
- C. 69
- D. 23
Explanation: Let the numbers be x and 6x because their ratio is 1:6. Their GCD is x and their LCM is 6x, so 6x = 138, giving x = 23 and the larger…
Correct answer: 138- A. 108
- B. 96
- C. 72
- D. 36
Explanation: For two numbers, product = GCD x LCM, so their product is 8 x 144 = 1152. If one number is 16, the other is 1152 ÷ 16 = 72.
Correct answer: 72- A. 28
- B. 32
- C. 40
- D. 64
Explanation: Write the numbers as 2x and 3x. Their LCM is 6x, so 6x = 48, giving x = 8; their sum is 2 x 8 + 3 x 8 = 40.
Correct answer: 40- A. 99
- B. 101
- C. 176
- D. 182
Explanation: Use prime factorisation and the divisor formula. 99 = 3^2 x 11 has 3 x 2 = 6 divisors, 101 has 2, 176 = 2^4 x 11 has 5 x 2 = 10, and 182 =…
Correct answer: 176- A. 123
- B. 127
- C. 235
- D. 305
Explanation: Subtract each remainder from its number: 1657 - 6 = 1651 and 2037 - 5 = 2032.
Correct answer: 127- A. 26 min 18 sec
- B. 42 min 36 sec
- C. 45 min
- D. 46 min 12 sec
Explanation: They return to the starting point together after the LCM of their lap times.
Correct answer: 46 min 12 sec- A. 3
- B. 13
- C. 23
- D. 33
Explanation: The required sum must be divisible by LCM(5, 6, 4, 3) = 60. Since 2497 = 60 x 41 + 37, the least addition is 60 - 37 = 23, giving 2520…
Correct answer: 23