A fair die is thrown 20 times. The probability that on the 10th throw, the fourth six appears is a.`"^20 C_(10)xx5^6//6^(20)` b. `120xx5^7//6^(10)` c. `84xx5^6//6^(10)` d. none of these

A fair die is thrown 20 times. The probability that on the 10th throw, the fourth six appears is ^20 C_(10)xx5^6//6^(20) b. 120xx5^7//6^(10) c. 84xx5^6//6^(10) d. none of these

A fair die is tossed eight times. The probability that a third six is observed in eight throw is (\ ^7C_(10)xx5^7)/(6^7) b. (\ ^7C_2xx5^2)/(6^8) c. (\ ^7C_2xx5^5)/(6^6) d. none of these

A fair die is tossed eight xx.The probability that a third six observed in eight throw is (7C_(10)xx5^(7))/(6^(7)) b.(7C_(2)xx5^(2))/(6^(8)) c.(7C_(2)xx5^(5))/(6^(6))d none of these

The sum of 20 terms of a series of which every even term is 2 times the term before it, every odd term is 3 times the term before it, the a. (2/7)(6^(10)-1) b. (3/7)(6^(10)-1) c. (3/5)(6^(10)-1) d. none of these

A die is thrown 560 times. The number 6 appears on the upper face 72 times. A die is thrown at random. What is the probability of getting 6.

A die is thrown 560 times. The number 6 appears on the upper face 72 times. A die is thrown at random. What is the probability of getting 6.

The sum of the first 20 terms of the series (1)/(5xx6)+(1)/(6xx7)+(1)/(7xx8)+backslash is (a) 0.16(b)1.6c(c)16(d) None of these

In 10 independent throws of a defective die, the probability that an even number will appear 5 times is twice the probability that an even number will appear 4 times. Find the probability that an even number will not apper at all in 10 independent throws of the die.

Radium has atomic weight 226 and half life of 1600 years. The number of disintegrationsd produced per second from one gram is a. 4.8 xx 10^(10) b. 3.7 xx 10^(20) c. 9.2 xx 10^(6) d. 3.7 xx 10^(8)