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The probability that A hits a target...

The probability that A hits a target is `1/3` and the probability that B hits It is `2/5` . What is the probability that the target will be hit , if each one of A and B shoots the target ?

A

`5/6`

B

`3/5`

C

`11/15`

D

`1/6`

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to find the probability that at least one of A or B hits the target when both shoot at it. We can use the formula for the union of two probabilities. ### Step-by-Step Solution: 1. **Identify the probabilities:** - The probability that A hits the target, \( P(A) = \frac{1}{3} \) - The probability that B hits the target, \( P(B) = \frac{2}{5} \) 2. **Use the formula for the probability of the union of two events:** \[ P(A \cup B) = P(A) + P(B) - P(A \cap B) \] Here, \( P(A \cup B) \) is the probability that at least one of them hits the target. 3. **Calculate \( P(A \cap B) \):** - Since A and B are independent events, we can find the probability that both A and B hit the target by multiplying their probabilities: \[ P(A \cap B) = P(A) \times P(B) = \frac{1}{3} \times \frac{2}{5} = \frac{2}{15} \] 4. **Substitute the values into the union formula:** \[ P(A \cup B) = P(A) + P(B) - P(A \cap B) \] \[ P(A \cup B) = \frac{1}{3} + \frac{2}{5} - \frac{2}{15} \] 5. **Find a common denominator:** - The least common multiple (LCM) of 3, 5, and 15 is 15. We will convert each fraction: \[ P(A) = \frac{1}{3} = \frac{5}{15}, \quad P(B) = \frac{2}{5} = \frac{6}{15}, \quad P(A \cap B) = \frac{2}{15} \] 6. **Perform the addition and subtraction:** \[ P(A \cup B) = \frac{5}{15} + \frac{6}{15} - \frac{2}{15} = \frac{5 + 6 - 2}{15} = \frac{9}{15} \] 7. **Simplify the result:** \[ P(A \cup B) = \frac{9}{15} = \frac{3}{5} \] ### Final Answer: The probability that the target will be hit if each one of A and B shoots the target is \( \frac{3}{5} \). ---
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ARIHANT SSC-PROBABILITY-INTRODUCTORY EXERCISE -(20.4)
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  13. The price of an article of rs100 is icreased by 20% the again its pric...

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  14. If 50% of (x-y) = 30% of (x+y), then what percent of x is y?

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  18. A speaks truth in 60% and Bin 80% of the cases. In what percentage of ...

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  19. One fifth of a number is 62. What will 73% of that number be?

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  20. Two third of three fourths of one fifth of a number is 15. What is 30%...

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