Question

There are 5 blue balls, 6 black balls in basket 1 and 7 blue balls and 3 black balls in basket 2 respectively. If we take one ball from each basket, what is the probability of both balls being blue?

• A. $\frac{35}{110}$
• B. $\frac{11}{110}$
• C. $\frac{11}{10}$
• D. $\frac{10}{11}$

Answer 1

The correct option is A $\frac{35}{110}$

Total no. of balls in basket 1
$=5+6=11$
Total no. of balls in basket 2
$=7+3=10$

$\therefore$ Total no. of ways we can select two balls $=11\times 10=110$

No. of blue balls in basket 1 and basket 2 are 5 and 7 respectively.

$\therefore$ Total no. of pairs of both being blue
$=5\times 7$ = $35$
For an event $E$,$P\left(E\right)=\frac{\text{Outcomes favourable to E}}{\text{Total no. of outcomes}}$

$\therefore$ P (Both being blue balls) $=\frac{35}{110}$