9) a) Find the surface area of this right rectangular prism. 420 m²
a.
b. 300 m²2
c. 600 m²
d. 480 m²
15 m
6 m
10 m
b) Marcelo has a bag that contains 3 red, 1 blue, 6 green, and 2
yellow marbles. What fractional part of the bag of marbles is red?

a) The surface area of a right rectangular prism is given by the formula `2lw + 2lh + 2wh`, where `l`, `w`, and `h` are the length, width, and height of the prism respectively. Plugging in the values for this prism, we get `2(15)(6) + 2(15)(10) + 2(6)(10) = 180 + 300 + 120 = 600`. So the surface area of this right rectangular prism is **600 m²**.

b) Marcelo has a total of `3 + 1 + 6 + 2 = 12` marbles in his bag. The fractional part of the bag that is red is `3/12` which can be simplified to **1/4**.