Question 7

The probability of selecting 1 black ball, then 1 red ball, and then 1 white ball is 7/200.

To find the probability of selecting 1 black ball, then 1 red ball, and then 1 white ball with replacement, we calculate the probability of each selection and multiply them together. The total number of balls is 40, so the probabilities are 14/40 for black, 10/40 for red, and 16/40 for white, leading to a final probability of (14/40) * (10/40) * (16/40) = 7/200.

A) 7/200

This option is correct as it accurately represents the calculated probability of selecting one black ball, one red ball, and one white ball in succession with replacement. The calculations yield a probability of 7/200, confirming its validity.

B) 7/100

This option is incorrect. Although it shares a similar numerator with the correct option, the denominator is not aligned with the total number of outcomes. The correct denominator should account for three selections from a total of 40 balls, leading to a final probability that does not match 7/100.

C) 21/200

This option is also incorrect. The numerator and denominator do not reflect the probability calculations for the selections made. The correct probability requires multiplying the individual probabilities, which results in a different fraction than 21/200.

D) Jul-50

This option is incorrect as it does not represent a valid probability format. Probabilities must be expressed as fractions or decimals within the range of 0 to 1, and "Jul-50" does not conform to this standard and is irrelevant in the context of this question.

Conclusion

The correct answer is 7/200, which accurately reflects the probability derived from the calculations of selecting one black, one red, and one white ball with replacement. All other options fail to represent the correct probability due to inaccuracies in their calculations or formatting, solidifying option A as the definitive answer.