Six identical coins are arranged in a row. The number of ways in which the number of tails is equal to the number of heads is

Question

Six identical coins are arranged in a row. The number of ways in which the number of tails is equal to the number of heads is (A) 20 (B) 9 (C) 120 (D) 40

Tardigrade Admin · Accepted Answer

Required number of ways =(6 !/3 ! 3 !) =(720/6 × 6)=20 [No. of heads =3, no. of tails =3 and coins are identical]

Q. Six identical coins are arranged in a row. The number of ways in which the number of tails is equal to the number of heads is

20

9

120

40

Required number of ways $= \frac{6 !}{3 ! 3 !}$
$= \frac{720}{6 \times 6} = 20$
[No. of heads $= 3$ , no. of tails $= 3$ and coins are identical]

Q. Six identical coins are arranged in a row. The number of ways in which the number of tails is equal to the number of heads is

20

9

120

40

Required number of ways =3!3!6!​ =6×6720​=20 [No. of heads =3, no. of tails =3 and coins are identical]

Required number of ways $= \frac{6 !}{3 ! 3 !}$
$= \frac{720}{6 \times 6} = 20$
[No. of heads $= 3$ , no. of tails $= 3$ and coins are identical]