Question

If aₙ = n(a ₙ-₁) and a₁ = 1, what is the value of a₅?

Answer 1

Answer:

The correct answer is Option c (120).

Step-by-step explanation:

The given value is:

$a_1=1$

$a_n=n(a_{n-1})$....(equation)

On putting the value of $a_1$ in the above equation, we get

⇒ $a_2=2(a_{2-1})$

        $=2(a_1)$

        $=2\times 1$

        $=2$

⇒ $a_3=3(a_{3-1})$

        $=3(a_2)$

        $=3\times 2$

        $=6$

⇒ $a_4=4(a_{4-1})$

        $=4(a_3)$

        $=4\times 6$

        $=24$

hence,

⇒ $a_5=5(a_{5-1})$

        $=5(a_4)$

        $=5\times 24$

        $=120$

Thus the above is the correct solution.