Question
Three boxes B1, B2, B3 contain red and green balls in
the ratio 1:1, 3:5, and 5:3 respectively. A box is selected at random and a ball is drawn. What is the probability that the selected ball is red?Solution
We are given:
- Three boxes: B1, B2, B3
- Each is equally likely to be chosen ⇒ P(B1) = P(B2) = P(B3) = 1/3
- Ball is drawn from the selected box
- Ratios of red to green balls:
- B1: 1 : 1 ⇒ Red = 1/2
- B2: 3 : 5 ⇒ Red = 3 / (3 + 5) = 3/8
- B3: 5 : 3 ⇒ Red = 5 / (5 + 3) = 5/8
= (1/3)·(1/2) + (1/3)·(3/8) + (1/3)·(5/8)
= (1/6) + (1/8) + (5/24) Now take LCM = 24:
- (1/6) = 4/24
- (1/8) = 3/24
- (5/24) = 5/24
The income of ‘A’ increases by 10% every year. If his income 2 years hence from now will be Rs. 27951, then find his income a year before from now.<...
Elina allocates her total salary as follows: she pays 8% as tax, then from the remaining amount, she spends 30% on rent, 20% on education, and Rs. 4500 ...
Anita has some money left after spending 20%, 10% and 30% of monthly salary on rent, electricity and shopping respectively. The remaining money with Ani...
In a given years, A sold 1450 caps while B sold 35% more number of caps than A and C sold 20% less number of caps than B. Find the ratio between the num...
A fruit seller bought 186 bananas at the rate of ₹72 per dozen. He found that 36 bananas were rotten and could not be sold. He sold the remaining bana...
If A's height is 40% less than that of B, how much percent B's height is more than that of A?
...The respective ratio of monthly income of A to monthly income of B is 11:12, and A’s saving is (100/17)% more than B’s saving. Find the expenditure ...
A gave 40% of amount to B. B gave 60% of amount received from A to C. If amount received by C from B is Rs.288, then find the amount received by B from A.
- X is 40% less than Y and Z is 30% more than W. If W is 25% more than X, then which of the following is true?
The price of a product P was increased by 60% and then decreased by 25%. After these changes, the prices of products P and Q are in the ratio 9:7. If th...
Relevant for Exams:
