Thinking Makes us Strong 2

We know that,

$8! =1 \times 2 \times 3 \times 4 \times \ldots \times 8 = 40320$

$6! = 1 \times 2 \times 3 \times \ldots \times 6 = 720$

$5! = 1 \times 2 \times \ldots \times 5 = 120$

Now,

• You have 40320 books.

$\huge \color{#D61F06} 40320 ~ \text{books}$

• You give 720 books to your friend.

$\huge \color{#3D99F6}40320 - 720 = \color{#20A900}39600 ~ \text{books}$

• You obtained 6 books from your uncle.

$\huge \color{#EC7300} 39600 + 6 = \color{#3D99F6} \boxed{39606 ~ \text{books}}$