Question

What is the maximal greatest common divisor of 6 different natural numbers written with 2 digits?

• A. $13$
• B. $15$
• C. $16$
• D. $18$

Answer 1

The correct option is A $13$

$(GCD{)}_n<100$

GCD must be prime number.

n must be between 1 to 6.

If GCD = 17 then $17x6=102>100$

$\therefore$ GCD = 13 (less prime than 17)