Question
A bag contains 13 white and some black balls. If the
probability of drawing a black ball from the bag is 3 times that of drawing a white ball, find the number of black balls in the bag.Solution
Given, Number of white balls = 13 Let x be the number of black balls. Total number of balls in the bag = 13 + x Also, the probability of drawing a black ball from the bag is 3 times that of drawing a white ball. ⇒ x/(13 + x) = 3[13/(13 + x)] ⇒ x = 39 Hence, the number of black balls in the bag = 39.
What will come in place of the question mark (?) in the following series?
1528, 1416, 1204, ?, 480, -32
143 Â Â Â Â 119Â Â Â Â 107Â Â Â Â 101Â Â Â Â Â 98Â Â Â Â ?
96 89 ? 90 94 91
...What value should come in the place of (?) in the following number series?
19, 235, 260, 324, 333, ?
What will come in place of the question mark (?) in the following series?
305...
In each of the following number series, one term is missing. Find the missing term.
3, 5, 20, 24, 144, 150, ?
1029, 1030, 1039, 1064, ?, 1194
75, 80, 95, ?, 155, 200
What will come in place of the question mark (?) in the following series?
1515, 184, ?, 455, 967, 624
7 29 61 ? 211 349
...
