Question

The probability that a certain type of missile will hit the target on any one firing is 0.80. How many missiles should be fired so that there is at least 98% probabil- ity of hitting the target at lest once?

Answer 1

Solution:-

=> P(all n misses) < 2%

So we have : (0.2)^n < 0.02

take logs: ln(0.2)^n < ln(0.02)

n*ln(0.2) < ln(0.02)

n >= ln(0.02)/ln(0.2)

n >= 2.4306

n >= 3