Product of Two Numbers = HCF X LCM of the Two Numbers

Q.

If L.C.M. (150, 100) = 300, then find H.C.F. (150, 100).

1. 50

2. 45

3. 75

4. 25

Q. If the prime factorisation of a and b are $a=2^2\times 3\times x$ and $b=2\times 3^2\times y$ ; LCM of (a, b) =$2^2\times 3^2\times 5^2$ and HCF of (a, b) = $2\times 3\times 5$, which of the following is true? ($x\ne 1,y\ne 1$)

1. xy = 25
2. x + y = 30
3. x – y = 0
4. x = 6

Q.

If the HCF of 60 and 168 is 12, what is the LCM?

1. 420

2. 840

3. 240

4. 480

Q.

HCF of two numbers is 1 and LCM is 221. If one of the two numbers is 17, find the other.

1. 200

2. 17

3. 39

4. 13

Q.

If L.C.M. (150, 100) = 300, then find H.C.F. (150, 100).

1. 25

2. 45

3. 50

4. 75

Q.

HCF of two numbers is __ given that their LCM is 210 and the numbers are 42 and 70.

Q.

If $a=p^l.q^m.r^n$ and $b=p^x.q^y.r^z$ where p, q, r are primes and p<q<r and l, m, n, x, y, z are all natural numbers. Given HCF = $p^2$.$q^3.r$ and LCM = $p^3$.$q^4$.$r^3$, which one of the following is NOT true?

1. l + m + n = x + y + z

2. l + x = 5

3. m + y = 7

4. n + z = 4

Q.

Find the HCF of 96 and 404 by the prime factorisation method. Hence, find their LCM.

Q.

For two numbers 96 and 404, the HCF is 4. What is the LCM of the two numbers?

1. 9696

2. 9600

3. 9698

4. 9700

Q. HCF of 36 and 45 is 9. Their LCM will be:

1. 180
2. 660
3. 160
4. 100