# 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. Q 1 - Reduce 128352238368 to its lowest terms.

A - 713

B - 34

C - 513

D - 913

### Explanation

Q 2 - The L.C.M of 22,54, 108, 135 and 198 is?

A - 5940

B - 5420

C - 5400

D - 5900

### Explanation

`L.C.M = 2 x 3 x 3 x 3 x 11 x 2 x 5 = 5940`

Q 3 - The least number, which when divided by 12,15,20 and 54 leaves in each case a remainder of 8, is?

A - 500

B - 548

C - 544

D - 536

### Explanation

`Required number = (L.C.M of 12, 15, 20, 54) + 8 = 540 + 8 = 548.`

Q 4 - The L.C.M of two numbers is 48. The numbers are in the ratio 2:3. The sum of the number is?

A - 40

B - 45

C - 50

D - 60

### Explanation

```Let the numbers be 2z, and 3z. then their L.C.M = 6z
So, 6z = 48 or z = 8.
Therefore the numbers are 16 and 24
Hence the required sum = 40.```

Q 5 - L.C.M of two prime numbers a and b(a>b) is 161. The value of 3b - a is?

A - -1

B - -2

C - 1

D - 2

### Explanation

```H.C.F of two prime numbers is 1. Product of numbers = (1 x 161) = 161
Let the numbers be a and b. Then a x b = 161
now co-primes with product 161 are (1, 161) (7,23).
Since a and b are prime numbers and a > b, we have a = 23 and b = 7.
Therefore  3b - a = (3 x 7) - 23 = -2.```

Q 6 - If the L.C.M of A and B is C, their H.C.F. is

A - C/AB

B - ABC

C - (A+B)/C

D - AB/C

### Explanation

```HCF*LCM=A*B
⇒HCF=(A*B)/LCM=AB/C```

Q 7 - Which greatest possible length can be used to measure exactly 165 cm, 330 cm and 440 cm.

A - 5

B - 15

C - 50

D - 55

### Explanation

`HCF of 165 cm, 330 cm and 440 cm is 55 cm.`

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

### Explanation

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

Q 9 - The H.C.F of three numbers is 12 and they are in the ratio of 1:2:3, find the numbers.

A - 6, 12, 18

B - 10, 20 ,30

C - 12, 24, 36

D - 24, 48, 72

### Explanation

```Let the numbers be a, 2a , 3a . Then , their H.C.F is a.
∴  a =12  and hence , the numbers  are 12, 24, 36.```

Q 10 - Three numbers are in the ratio of 3:4 :5 , their L.C.M is 2400. Their H.C.F is :

A - 40

B - 80

C - 120

D - 160

### Explanation

```Let the numbers be 3x, 4x and 5x.
Then L.C.M =  60x
60x= 2400   ⇒ x= 40
∴ The numbers are 120, 160 and 200.
Clearly , their H.C.F is 40 ```

aptitude_hcf_lcm.htm 