Question

What are the different combinations of $2$ digits possible out of $6$ digits $1,2,3,4,5,6$?

• A. $6$
• B. $15$
• C. $24$
• D. $12$

Answer 1

The correct option is B $15$

Given that $2$ digits are selected out of $6$ given digits.

We have to find all the "different" combinations to select $2$ digits, order of digits does not matter.

So, possible combinations are
$(1,2)(1,3)(1,4)(1,5)(1,6)$
$(2,3)(2,4)(2,5)(2,6)$
$(3,4)(3,5)(3,6)$
$(4,5)(4,6)$
$(5,6)$

Total $15$ different combinations are possible.