A dice is rolled until an ace (1) shows. What is the probability that an ace will show on the fourth try?1. A die is rolled until an ace (1) shows. What is the

Question

 

 

Try to think what is the probability of an ace NOT showing on the first try, then on the second try, the third try, then showing on the fourth try and multiply them all.

Answer 1

Hy Pam,

 

A die  has 6 sides so the total probability is 6.

 

probability of a no show on first = 5/6

 

on the second = 5/6

 

on the third = 5/6

 

Now on the fourth one = 1/6

 

since there is only one ace out of 6 possible numbers

 

Finally

 

P = (5/6)^3 (1/6)

 

= 125 / 216 (1/6)

 

= 125 / 1296

 

 

You can use a calculator if needed.

 

 

Good luck.

 

Mayuran