2022/070) 7 dices are rolled. What s the probabilty that the sum of top faces is 10 ?

 For eah dice there are 6 outcomes

for 7 dices there are $6^7$ outcomes

so there are $5^7$ out comes

10 can come in followin ways

6 ones and a 4 this can come in 7 ways(4 at any of 7 places)

5 ones one 2 and one 3 this can come in 7 * 6 = 42 ways( 2 at any of  7 places and and then 3 in any of the next 6 paces)

4 ones and 3 twos = $7 \choose 3$ = 35 places

so total number of places = 7 + 42 + 35 = 84.

so probability = $\frac{84}{6^7}$