Question

A box contains 6 red and 4 white marbles. A marble is drawn and replaced three times from the box. The probability that one white marble is drawn

• A. $53/125$
• B. $54/125$
• C. $56/125$
• D. $52/125$

Answer 1

The correct option is B $54/125$

Total balls are $=$ 6 Red and 4 White marbles $=$ 10 balls
Case when one white marble is drawn $=$ 1 White and 2 Red marbles
W R R; R W R; R R W
Probability that one white marble is drawn $=$ $3\times \left(\frac{{}^4{C}_1}{{}^{10}{C}_1}\right)\times \left(\frac{{}^6{C}_1}{{}^{10}{C}_1}\right)\times \left(\frac{{}^6{C}_1}{{}^{10}{C}_1}\right)=\frac{54}{125}$