If X and Y are independent random variables and Var(X)=Var(Y)=4, then find Var(2X-3Y+1)?
Var(2X-3Y+1) = (2)^2*VarX + (3)^2*Var(Y) + Var(1) = 4*4+ 9*4 = 16+36 = 52 Since, variance of constant is 0, so Var (1) is 0.
B is 3 years older than A and A is 7 years older than C. If the sum of the age of A and C is 27 years, then find the sum of the ages of all three.
Average age of 4 daughter of a family is 8 years and average age of daughter together with their parents is 16 years. If mother is 4 years younger than...
The ratio of the ages of Pari and Qureshi is 5:9. If the ratio of the age of Pari after 3 years and the age of Qureshi after 9 years is 1:2, then find t...
The ratio of A and B present age is 4:3. The product of their ages is 4800. What will be the ratio of their ages after 5 years?
A lad was asked his age by his friend. The lad said “The number you get when you subtract 25 times my age from twice the square of my age will be thri...
The ratio of the ages of A, B and C, 5 years ago, was 4 : 5 : 7. The sum of their present ages is 135 years. What will be the sum of the ages (in years...
A is younger than B by 4 years. If the ratio of A and B ages is 5:7 respectively, then find the age of A.
Seven years ago, the sum of the ages of a mother and her daughter was 46 years. The ratio of their present ages is 3 : 1. What is the present age of the...
The ratio of age of A and his son is 9:3. If the difference of their ages 6 years ago is 36, then find the sum of the ages of A and his son together 4 y...
A is 3 years older than B while C is 5 years younger than B. The ratio of age of A, 6 years hence and age of B, 3 years ago is 4:3. What was age of C, 1...
