Question

All numbers divisible by both 12 and 20 are also divisible by which of the following?
Choose 1 answer:
A 41
B 30
C 21
D 13
E 23

Answer 1

Answer:

B.30

Step-by-step explanation:

Because 12 and 20 both are even numbers so answer would be 30 since it's the only even number here.

You can explain it by following example,

Let us consider a number 48 it is divisible by both 12 I.e. 2 and 20 I.e. 2.4 now,

48/41...1.170731707...

48/30...1.6 (Its the only finite number)

48/21...2.285714...

48/13...3.692307...

48/23...2.086956...

Answer 2

Answer:

There are 7 steps in this answer:-

Step-by-step explanation:

1. A number is divisible by another number (a divisor) if its prime factorization contains the prime factorization of the divisor.

2. The prime factorization of 12 is 2 x 2 x 3.

3. The prime factorization of 20 is 2 x 2 x 5.

4. So, any number divisible by both must have 2 x 2 x 3 x 5 as part of its prime factorization.

5. All numbers which divide such a number will have a factorization which is part of 2 x 2 x 3 x 5.

6. The prime factorization of 30 is 2 x 3 x 5.

7. Since 2 x 3 x 5 is part of 2 x 2 x 3 x 5, all numbers which are divisible by 12 and 20 are also divisible by 30.