There are 3 different mathematics books and 4 different physics books on a shelf. Then the number of ways these books can be arranged so that the mathematics books are together is

Question

Smart Achievers · Accepted Answer

(4)

Taking all 3 Mathematics books as a single unit and 4 different Physics books as 4 different units, we have 5 units which can be arranged in $5!$ ways.

Also, 3 Mathematics books can be arranged in $3!$ ways.

$∴$ Required number of ways = $5! \times 3! = 120 \times 6 = 720$

Solution

Q.
There are 3 different mathematics books and 4 different physics books on a shelf. Then the number of ways these books can be arranged so that the mathematics books are together is

1 144

2 120

3 520

4 720

Ans.
(4)

Taking all 3 Mathematics books as a single unit and 4 different Physics books as 4 different units, we have 5 units which can be arranged in $5!$ ways.

Also, 3 Mathematics books can be arranged in $3!$ ways.

$∴$ Required number of ways = $5! \times 3! = 120 \times 6 = 720$

Want Us to Email you About Special Offers & Updates?