Can we identify the exact value of a positive integer x?
(1) Only. x can be 1 or 2. Not Sufficient.
(2) Only. Evidently insufficient.
(1) and (2) Together.
12 = 4*3 = 2^2 * 3. It contains 3*2=6 factors and is a factor of the product.
20 = 4*5 = 2^2 * 3. It contains 3*2=6 factors and is a factor of the product.
Not Sufficient.
Answer is
(E).
How to come up with the number of 12 and 20?We can find the number of factors of a given number using the following steps. (Read more from
https://www.cuemath.com/numbers/factors/)
Step 1: Find its prime factorization, i.e. express it as the product of primes.
Step 3: Write the prime factorization in the exponent form.
Step 3: Add 1 to each of the exponents.
Step 4: Multiply all the resultant numbers. This product would give the number of factors of the given number.
The product = 1 * 2 * 3 * 4 * 5 = 2^3 * 4 * 5
Condition (2) stipulates that x have 6 = 3 * 2 factors = (2+1)*(1+1) factors.
We have to pick 2^2 to supply (2+1)
then, we can pick either 3 or 5 to supply (1+1)