A) \[\frac{316}{25}{{\left( \frac{4}{5} \right)}^{48}}\]
B) \[\frac{54}{5}{{\left( \frac{4}{5} \right)}^{49}}\]
C) \[\frac{164}{25}{{\left( \frac{1}{5} \right)}^{48}}\]
D) \[\frac{201}{5}{{\left( \frac{1}{5} \right)}^{49}}\]
Correct Answer: B
Solution :
Let X be random varibale which denotes number of problems that candidate is unbale to solve \[\because \]\[p=\frac{1}{5}\]and\[X<2\] \[\Rightarrow P(X<2)=P(X=0)+P(X=1)\] \[={{\left( \frac{4}{5} \right)}^{50}}+{}^{50}{{C}_{1}}.\left( \frac{1}{5} \right).{{\left( \frac{4}{5} \right)}^{49}}\]You need to login to perform this action.
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