Question

If on an average 1 ship in every 10 sinks,find the chance that out of 5 ships atleast 4 will arrive safely.

Answer 1

Attempt:
Net P=P(4)+P(5)
Using Bernoulli trials>
\[\Large C(5,4) (1-\frac{1}{10})^4 (\frac{1}{10})^1+C(5,5) (1-\frac{1}{10})^5\]

Answer 2

\[\LARGE 5 \times (\frac{9}{10})^4 \times \frac{1}{2}+ (\frac{9}{10})^5\]

Answer 3

\[\LARGE \frac{9^4}{10^5}(5+9)= \frac{9^4}{10^5} \times 14\]

Answer 4

=0.98

Answer 5

answer is 0.9185

Answer 6

oops a little mistake

Answer 7

\[\LARGE (\frac{9}{10})^4 \times \frac{1}{2}+ (\frac{9}{10})^5\]

Answer 8

\[\LARGE \frac{9^4}{10^4}(1+0.9)=\frac{9^4}{10^4}(1.9)\]

Answer 9

=1.24 o.O

Answer 10

duh! silly mistakes got it thanks