Question
A bag contains 5 red balls, 6 blue balls, and 9 green
balls. Two balls are drawn at random without replacement. What is the probability that both balls are of the same color?Solution
Total balls = 5 + 6 + 9 = 20 balls. The number of ways to select 2 balls out of 20 = C(20, 2) = (20 × 19) / 2 = 190. Number of ways to select 2 red balls = C(5, 2) = (5 × 4) / 2 = 10. Number of ways to select 2 blue balls = C(6, 2) = (6 × 5) / 2 = 15. Number of ways to select 2 green balls = C(9, 2) = (9 × 8) / 2 = 36. Total favorable outcomes = 10 + 15 + 36 = 61. Probability = 61 / 190 = 11 / 42. Correct Option: a
A man has Rs. 15,000 with him. He gives away 12% of this for charity, 15% of the remaining amount for education, and 20% of the new remaining amount for...
In a two digit positive number, the digit in the unit’s place is equal to the square of the digit in ten’s place, and the difference between...
A boy lost his 25% of his money. After spending 30% of the remainder, he has Rs 1260 left. What money does he had initially?
Mohan goes to a sports shop with some money. He can buy 100 footballs or 50 basketballs with the money with him. However, instead of spending the entire...
In a survey conducted in a locality, it was found that 50% read newspaper A, 40% read newspaper B, and 20% read neither A nor B. If the number of person...
50% students (boys + girls) in a math class are boys. Out of total boys, 65% are literate and 70 are illiterate. Find the number of literate girls in th...
Income of Aakash is 66â…”% more than the expenditure of Bhavya. Income of Bhavya is 25% more than the expenditure of Aakash. If savings of Bhavya is Rs....
In an examination having total 300 questions, in the first section having 180 questions. A student got 75% marks in first section, but he got 83% marks ...
- Income of Arjun is 70% more than that of Tarun. Arjun saves 50% of his income, Tarun saves 30%. If their expenditure difference is Rs. 1050, what are Arjun...
A student multiplied a number by 2/5 instead of 5/2 . What is the percentage error in the calculation?
Relevant for Exams:
