Question

If sum of three prime numbers is $r$ where two numbers out of three are twin prime numbers and $r$ is an even number less than $20,$ then product of the numbers can be

• A. $15$
• B. $30$
• C. $35$
• D. $70$

Answer 1

Answer: (B), (D)

The correct options are
B $30$
D $70$

Since, $r$ is an even number.
There are two cases
Case-$1:$ all three numbers are even (which is not possible)
Case-$2:$ any one is even and other two are odd.
So, one number will be definitely $2.$
Other numbers are twin prime numbers, so possibilities are
$(3,5),(5,7)$
So, product can be
$2\times 3\times 5=30$ or $2\times 5\times 7=70$