If four hats are picked at random, what is the probability that one is green, two are blue and one is red?
Total number of hats = 6 + 4 + 2 + 4 = 16 Let S be the sample space. Then, n(S) = number of ways of drawing 4 hats out of 16 = ¹⁶C_4 = (16 × 15× 14 × 13 )/( 4 × 3 × 2 × 1) = 1820 Let E= event of drawing 4 hats so that one is green, two are blue and one is red = n(E) = ²C_1×⁴C_2×⁶C_1= 2 × 6 × 6= 72 ∴ P (E) = (n(E))/(n(S))= 72/1820 = 18/455
Anil’s present age is 3/8 of his father’s present age. Anil’s sister is 4 years older than him. The ratio between the present age of Anil’s fath...
If the total ages of A and B is 6 years more than the total age of B and C. C is how many years younger than A?
Present ages of 'A' and 'B' are in the ratio 3:5, respectively. If B's age, 8 years hence from now will be 3 times of A's age, 2 years ago from now, the...
A boy’s age is 125% of what it was 8 years ago, but 75% of what it will be after 8 years. What is his present age?
The present age of Surjeet and Rakesh are in the ratio of 4:5. After 8 years the ratio of their ages will be 6:7. What is 70% of the sum of their presen...
Amit age after 10 years will be 3 times his age 4 years back. What is the present age of Amit?
If the ratio of the ages of Karan and Saroj is 5 : 7. 8 years ago, the ratio of their ages was 2 : 3. Find the present age of Saroj?
In a classroom there are 11 boys and 9 girls. Average age of each boy and each girl is 18 years and 15 years respectively. The sum of ages of all the bo...
Present average age of 4 friends: ‘A’, ‘B’, ‘C’ and ‘D’ is 30 years. If their ages are in the arithmetic progression in the same order a...
B is 5 years older than A and A is 7 years older than C. If the sum of the age of A and C is 21 years, then find the sum of the ages of all three.
