Question 18

An unbiased dice is tossed seven times. Find the probability of getting a third six on the seventh throw.

Solution

We need a third 6 in the 7th throw which means that in the first 6 throws we should get 6 exactly twice.

No. of ways of getting 6 exactly twice in first 6 throws= $$^6C_2$$

Probability of getting 6 for the third time in the seventh throw= $$\frac{\left(^6C_2\times\ 5^4\right)}{6^7}$$


Create a FREE account and get:

  • All Quant Formulas and shortcuts PDF
  • 170+ previous papers with solutions PDF
  • Top 5000+ MBA exam Solved Questions for Free

cracku

Boost your Prep!

Download App