Assuming that each marble can be picked with equal probability, we notice that there is a total of

marbles, of which 2 are red.
So, the probability of picking a red marble is

In fact, as in any other case of (finite) equidistribution, we used the formula

Answer:
The new side lengths will be 24 inches and 40 inches
Step-by-step explanation:
Here, given the width and length of a rectangle and we want to create a scaled copy using a scale factor of 4, we want to know the new side lengths
What we simply want to do here is to scale up or dilate the side lengths of the rectangle using a scale factor of 4
Hence, the new side lengths will be (4 * 6) inches and (10 * 4) inches
The new side lengths will be 24 inches and 40 inches
The number of seats per row generate an arithmetic sequence. Let

denote the number of seats in the

-th row. We're told that the number of seats increases by 3 per row, so we can describe the number of seats in a given row recursively by

The total number of seats is given by the summation

Because

is arithmetic, we can easily find an explicit rule for the sequence.





So the number of seats in the

-th row is exactly

This means the total number of seats is

You should be familiar with the remaining sums. We end up with