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H.C.F & L.C.M. - Online Quiz
Following quiz provides Multiple Choice Questions (MCQs) related to H.C.F & L.C.M.. You will have to read all the given answers and click over the correct answer. If you are not sure about the answer then you can check the answer using Show Answer button. You can use Next Quiz button to check new set of questions in the quiz.
Answer : B
Explanation
99 = 1 x 3 x 3 x 11; 101 = 1 x 101; 176 = 1 x 2 x 2 x 2 x 2 x 11; 182 = 1 x 2 x 7 x 13. So, divisor of 99 are 1, 3, 9, 11, 33, 99 divisor of 101 are 1, 101 divisor of 176 are 1, 2, 4, 8, 16, 22, 44, 88, 176 divisor of 182 are 1, 7, 2, 13, 14, 26, 91, 182 Hence 176 has the most number of divisors.
Q 2 - H.C.F of 3240, 3600 and a third number is 36 and their L.C.M is 24 x 3 5 x 52 x 72?
Answer : B
Explanation
3240 = 23 x 32 x 5; 3600 = 24 x 32 52 H.C.F = 36 = 22 x 32. Since H.C.F is the product of the lowest powers of common factors so the the third number must have 22 x 32 as its factor Since L.C.M is the product of highest powers of common prime factors so the third number must have 35 x 72 as its factor Therefore third number = 22 x 35 x 72
Q 3 - The least number, which when divided by 12,15,20 and 54 leaves in each case a remainder of 8, is?
Answer : B
Explanation
Required number = (L.C.M of 12, 15, 20, 54) + 8 = 540 + 8 = 548.
Q 4 - The H.C.F of two numbers is 11 and their L.C.M is 7700. If one of the numbers is 275, then the other is?
Answer : B
Explanation
Other number = 11 x 7700⁄275 = 308
Q 5 - The greatest possible length which can be used to measure exactly the lengths 7m, 3m 85cm, 12m 95cm is?
Answer : B
Explanation
Required length = H.C.F of 700, 385, 1295 = 35 cms.
Q 6 - Find the least number which when divided separately by 13, 26, 39 and 52 leaves 5 as remainder in each case.
Answer : C
Explanation
Required number = L.C.M. of (13, 26,39 and 52) +5 = 156 + 5 = 161
Q 7 - X, Y and Z start at the same time in the same direction to run around a circular stadium. X completes a round in 126 seconds, Y in 154 seconds and Z in 99 seconds, all starting at the same point. After what time will they again at the starting point?
Answer : B
Explanation
L.C.M. of 126,154 and 99 = 1386. So, X, Y and Z will again meet at the starting point in 1386 sec. i.e., 23 min. 06 sec.
Q 8 - The ratio of two numbers is 2:3. Having their L.C.M as 150, numbers are :
Answer : C
Explanation
Let the numbers be 2x and 3x . Then, their L.C.M is 6x. 6x = 150 ⇒ x= 25 So, the numbers are 50 and 75.
Q 9 - H.C.F and L.C.F of two numbers x and y are 3 and 105 respectively. If x+y=36 then figure out 1/x + 1/y.
Answer : D
Explanation
We have X *y =3 *105 ⇒ xy = 315 ∴ x+y/xy =36/315 = 4/35 ⇒ 1/y+1/x = 4/35 ⇒ 1/x+1/y = 4/35.
Answer : C
Explanation
210 = 2*3*5*7, 315 =3*5*3*7 , 147 = 7*7*3 , 168 = 2*2*2*3*7 Required number = H.C.F of given numbers= (3*7) =21