Q15 of 46 Page 1

The probability of selecting a red ball at random from a jar that contains only red, blue and orange balls is 1/4. The probability of selecting a blue at random from the same jar is 1/3. If the jar contains 10 orange balls, find the total number of balls in the jar.

Let the no of red balls = x


Let the no of blue balls = y


No of orange balls = 10 [given]


Total No of balls = x + y + 10




4x = x + y + 10


y = 3x - 10 [Eqn 1]



3y = x + y + 10


2y - x = 10


2(3x - 10) - x = 10 [using eqn 1]


6x - 20 - x = 10


5x = 30


x = 6


y = 3(6) - 10 = 8


Total no of balls : x + y + 10 = 6 + 8 + 10 = 24


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