Prime Factorization and LCM of Two Numbers

Q.

H.C.F of two prime numbers is $1$.

1. True
2. False

Q.

Find the L.C.M.of $108,135,162$ by prime factorisation method

Q. The smallest number exactly divisible by 32, 36, 48, 96 is

1. 96
2. 108
3. 288
4. 576

Q.

Find the LCM by the method of division.

$8,24,48,80,102$

Q. Two boys start jogging together on a circular track. If they respectively take 30 minutes and 20 minutes to complete one round, when will they meet ?

1. after 50 minutes
2. after 60 minutes
3. after 40 minutes
4. after 90 minutes

Q. The Least Common Multiple of two relatively prime numbers $x$ and $y$ is equal to

1. $x+y$
2. 2($x+y$)
3. $x\times y$
4. $2\times x\times y$

Q. Least length of a rope which can be cut into pieces of length 8 cm, 18 cm and 24 cm is

Q. Which of the following is the minimum length of a rope which can be cut into pieces of length 7 cm or 9 cm or 10 cm?

1. 63 cm
2. 810 cm
3. 490 cm
4. 630 cm

Q.

Is $41$ a prime number?

Q.

Is $43$ a prime number?

Q. Find the smallest number that is completely divisible by $36$ and $48$.

1. 36
2. 144
3. 288
4. 72

Q.

A number is divisible by both $5$ and $12$. By which other number will that number be always divisible?

Q. Least common multiple of 50 and 55 is

1. 500
2. 2750
3. 550
4. 110

Q. Find least common multiple of 15, 25, 30

1. 100
2. 125
3. 90
4. 150

Q. Tom used to workout every 6 days and Sam every 7 days. Tom and Sam both did workout together today. After how many minimum days will they both workout together?

1. $21$
2. $42$
3. $36$
4. $84$

Q. Merry along with her family is going to picnic. She wants to pack equal number of apple slices and orange slices for snacks. She have boxes which can store either 27 apple slices or 36 orange slices. What is the minimum number of orange slices she can pack?

1. $108$
2. $120$
3. $144$
4. $132$

Q. 22320 is divisible by 9 and 8 so it must be divisible by

1. 27
2. 72
3. None of these

Q. There are wallpapers of two different sizes, $6{\text{feet}}^2$ and $8{\text{feet}}^2.$ What should be the minimum area of the wall, which can be fully covered using some identical wallpapers of any of given type?

1. $24{\text{feet}}^2$
2. $12{\text{feet}}^2$
3. $6{\text{feet}}^2$
4. $48{\text{feet}}^2$

Q. I am the smallest number which is 3 more than a number which is completely divisible by 15 and 20. Identify me.