Question
A bag contains 20 white and some black balls. If
the probability of drawing a black ball from the bag is 1.3 times that of drawing a white ball, find the number of black balls in the bag.Solution
Number of white balls = 20
Let x be the number of black balls.
Total number of balls in the bag = 20 + x
Also, the probability of drawing a black ball from the bag is 1.3 times that of drawing a white ball.
⇒ x/(20 + x) = 1.3 [20/(20 + x)]
⇒ x = 1.3 × 20 = 26
Hence, the number of black balls in the bag = 26
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115 ÷ 23 + 12 × 6 = ? + 16 - 35
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Simplify the given expression:-
[192 ÷ 6 × 5] ÷ (? + 3) = 20
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Solve.
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