Box a contains two red cards and one black card, and box b contains one red card and two black cards. an experiment consists of randomly selecting one card from box a and placing the selected card into box b. then, one card is selected from box b. what is the probability that a red card is selected from box b?

5/12

Step-by-step explanation:

Box A: 2 Red

           1 Black

Box B: 1 Red

           2 Black

One card is selected from Box A and placing the selected card into Box B.

One card is selected from Box B.

What is the probability that a red card is selected from Box B?

Two things can occur:

1) Select red from A and B:

2/3 * 2/4 = 1/3

2) Select black from A and red from B:

1/3 * 1/4 = 1/12

As 1) or 2) can occur:

1/3 + 1/12 = 5/12

answer: first option i.e. 'a' is correct.

step-by-step explanation:

since we have given that

number of minutes to wrap a small gift box = 4 minutes

we need to find the number of gifts to be wrapped in 5 minutes

since there is a direct variation, as the number of minutes will increase with   number of gifts to be wrapped.

so, let the number of gifts to be wrapped in 5 minutes be x.

so, it becomes,

hence, first option 'a'   is correct.