H.C.F & L.C.M. - Online Quiz


Advertisements


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.

Questions and Answers

Q 1 - Reduce 128352238368 to its lowest terms.

A - 713

B - 34

C - 513

D - 913

Answer : A

Explanation

Q 2 - The ratio of two numbers is 3:4 and their H.C.F is 4. Their L.C.M is?

A - 60

B - 80

C - 48

D - 58

Answer : C

Explanation

Let the numbers be 3x and 4x.
Then, their H.C.F = z
So, z = 4 
 So, the numbers are 12 and 16. L.C.M of 12 and 16 = 48.

Q 3 - Let the least number of six digit, which when divided by 4,6,10 and 15, leaves in each case the same remainder of 2. The sum of the digits N is?

A - 5

B - 323

C - 4

D - 623

Answer : A

Explanation

Least number of 6 digits  is 100000. L.C.M of 4,6,10 and15 = 60
On dividing 100000 by 60, the remainder obtained is 40.
Therefore Least number of 6 digits divisible by 4,6,10, and 15 = 100000 + (60 - 40) = 100020.
Therefore N = (100020 + 2) = 100022.
Sum of digits in N = (1 + 2 + 2) = 5.

Q 4 - The L.C.M of the two numbers is 495 and their H.C.F is 5. If the sum of the numbers is 10 then their difference is?

A - 15

B - 40

C - 10

D - 70

Answer : D

Explanation

Let the numbers be z and (100 - z). Then, z (100 - z) = 5 x 495
= z2 - 100z + 2475 = 0
(z - 55) (z - 45) = 0
z = 55 or z = 45 
 Therefore the numbers are 45 and 55. Required difference is (55 - 45) = 10

Q 5 - The H.C.F of two numbers is 23 and the other two factors of their L.C.M are 13 and 14. the larger of the two number is?

A - 276

B - 299

C - 322

D - 345

Answer : C

Explanation

clearly the numbers are (23 x 13) and (23 x 14)
Larger number = (23 x 14) = 322.

Q 6 - The least square number which is divisible by 12, 14 and 18 is:

A - 1764

B - 1600

C - 1444

D - 1296

Answer : A

Explanation

The least number divisible by12, 14 and 18 is their L.C.M. which is 252.
Now 252=2*2*3*3*7
To make it a perfect square, it must be multiplied by 7
2*2*3*3*7*7=1764

Q 7 - The G.C.D. of 0.93, 0.60 and 0.75 is:

A - 0.03

B - 0.06

C - 0.09

D - 0.12

Answer : A

Explanation

Given numbers are 0.93, 0.60 and 0.75.   H.C.F. of 93, 60 & 75 is 3.
 H.C.F. of given numbers = 0.03

Q 8 - The H.C.F and L.C.M of two numbers is 11 and 7700. If one of the numbers is 275, find the other number:

A - 279

B - 283

C - 308

D - 318

Answer : C

Explanation

Let the other number be x. than ,
11 * 7700 =  275 * X ⇒ x = (11* 7700)/275 = 308
Hence,  the number is 308.

Q 9 - If ratio of two numbers is 2:3 and the product of their H.C.F and L.C.M is 33750, find the sum of the numbers:

A - 250

B - 325

C - 375

D - 425

Answer : C

Explanation

Let the numbers be 2x and 3x.  Then, H.C.F = x and L.C.M = 6x
∴ 6x*x = 33750  ⇒ x2 = 5625   ⇒ &sqrt;5625= 75
So, the numbers are 150  and 225 . Their sum is 375.

Q 10 - What is the greatest length possible of a scale that can be used to measure exactly 7 m, 3 m 85 cm, 12 m 95 cm, is:

A - 15 cm

B - 25 cm

C - 35 cm

D - 42 cm

Answer : C

Explanation

Required length = H.C.F of 700 cm, 385 cm and 1295 cm= 35 cm


aptitude_hcf_lcm.htm

Advertisements