Question

Two persons entered a Railway compartment in which 7 seats were vacant.The number of ways in which they can be seated is

• A. $30$
• B. $42$
• C. $720$
• D. $360$

Answer 1

Answer: (B)

$42$

$\to$ The $1^{st}$ person can take any one of the 7 seats.
$\to$ The $2^{nd}$ person can take any one of the remaining 6 seats.
$\Rightarrow$ So, the total $=7\times 6=42$.