Question
A bag contains 4 green balls, 11 red balls, and 3 white
balls. Two balls are drawn at random. Find the probability that the two balls are red.Solution
Number of ways of selecting two red balls = 11 Câ‚‚
Total number of balls = 4 + 11 + 3 = 18
Number of ways of selecting two balls = 18 Câ‚‚
Probability = 11 C₂ ÷ 18 C₂ = (11 × 10) ÷ (18 × 17) = 110 ÷ 306 = 11/31
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?
