Question
A bag contains 2 black balls, 6 red balls, and 10 blue
balls. Two balls are drawn at random. Find the probability that the two balls are blue.Solution
Number of ways of selecting two blue balls = 10 Câ‚‚
Total number of balls = 2 + 6 + 10 = 18
Number of ways of selecting two balls = 18 Câ‚‚
Probability = 10 C₂÷ 18 C₂ = (10 × 9) ÷ (18 × 17) = 90 ÷ 306 = 5/17
The ratio of A’s age to B’s age is 5:7, and the sum of their ages after 6 years is 72 years. Find the present age of A.
- The total amount of money Garima, Radha, and Kiran have Rs. 18720, and Garima has Rs. 540 more than twice of what Radha has. If Radha has 35% more than Kir...
The ratio of the weights of Arjun, Ravi, and Sameer is 7:6:5 respectively. The weight of Karan is 9 kg less than the weight of Arjun. If the difference ...
The ratio of the number of English books to Hindi books in a library shelf is 6:5. If 135 Hindi books are written by Pradeep, which constitutes 15% of t...
In a class, the ratio of number of boys to number of girls is 9:4. If 5 boys joined the class and 1 girl left the class, then the ratio becomes 7:3. Fin...
Find the third proportional to 12 and 48?
The mean proportional of 4 and 25 is _____.
The ratio of P’s to Q’s salary is 5 : 7. If Q’s salary is increased by 35%, his total salary becomes Rs. 52,920. What is the salary of P?
...Three numbers are in ratio 3:5:6. If the sum of the squares of those three numbers is 280 then find the sum of the three numbers.
Find the third proportion of 12.5 and 16.
Relevant for Exams:
