JEE Main 2016 · 10 Apr · Shift 1 · Mathematics Q87

MathematicsSingle correct+4 / -1Question 87 of 90

An experiment succeeds twice as often as it fails. The probability of at least 5 successes in the six trials of this experiment is :

\dfrac{240}{729}

\dfrac{192}{729}

\dfrac{256}{729}

\dfrac{496}{729}

Answer and worked solution

Official answer: C

$p=\frac23$ : $P(\ge5)=6\left(\frac23\right)^5\frac13+\left(\frac23\right)^6=\frac{192+64}{729}=\frac{256}{729}$ .

JEE Main 2016 · 10 Apr · Shift 1, Mathematics question 87