A bag contains 7 green and 8 white balls. If two balls are drawn simultaneously, the probability that both are of the same colour is -
A. $$\frac{{8}}{{15}}$$
B. $$\frac{{2}}{{5}}$$
C. $$\frac{{3}}{{5}}$$
D. $$\frac{{7}}{{15}}$$
Answer: Option D
Solution (By Examveda Team)
Drawing two balls of same color from seven green balls can be done in $${}^7{C_2}$$ ways.Similarly from eight white balls two can be drawn in $${}^8{C_2}$$ ways.
$$\eqalign{ & P = \frac{{{}^7{C_2}}}{{{}^{15}{C_2}}} + \frac{{{}^8{C_2}}}{{{}^{15}{C_2}}} \cr & \,\,\,\,\,\,\, = \frac{7}{{15}} \cr} $$
This Question Belongs to Arithmetic Ability >> Probability
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