Question
A box holds 8 green balls, 7 blue balls, and 5 yellow
balls. Three balls are picked randomly. What is the probability that at least two balls are blue?Solution
ATQ,
Required probability = (Two blue balls and one either green or yellow) + (Three blue balls) = 3 × [(7/20) × (6/19) × (13/18)] + (7/20) × (6/19) × (5/18) = (3276/6840) + (210/6840) = (3486/6840) = 29/57
625, 250, 100, 40, 16, 6
Find the wrong number in the given series.
2827, 2863, 2811, 2867, 2819, 2871
Find the wrong number in the given number series.
 289, 274, 260, 247, 235, 225
556, 547, 483, 458, 242, 196
213, 215, 225, 257, 313, 393
164, 160, 172, 136, 188, 128
Find the wrong number in the given number series.
237, 526, 165, 608, 77, 702
128, 173, 196, 189, 176, 133
12, 14, 18, 26, 38, 64
- In the given number series, find the wrong number.
1, 4, 9, 16, 25, 38, 49