Question

1. If 3 is the least prime factor of a number x and 2 is the least prime factor of another number y, then the least prime factor of the number 2x + 5y is (a) 2 (b) 3 (c) 5 (d) 6

Answer 1

Answer:

Let x = 3p and y = 2q

So 2x + 5y

→ 2*3p + 5*2q

→ 2(3p + 5q)

2|2x + 5y

Hence 2 is the least prime factor of 2x + 5y

Answer: (a) 2

Step-by-step explanation:

Answer 2

Given:

• 3 is the least prime factor of a number x
• 2 is the least prime factor of another number y

To find:

Least prime factor of the number 2x + 5y

Solution:

If 3 is the least prime factor of a number x then the number x would be in the form of 3m.

And 2 is the least prime factor of another number y so y is equivalent to 2n

then;

• 2.3m + 5.2n
• 6m + 10n
• 2(2m + 5n)

Hence, the least prime factor of the number 2x + 5y is 2