Geometry assistance needed, so much

What is the equation and solution for the sentence? the sum of a number and thirty-one is one hundred thirteen. write the equation as n-31=113 and subtract 31 from both sides. the answer is 82. write the equation as n+31=113 and subtract 31 from both sides. the answer is 82. write the equation as n+31=113 and add 31 to both sides. the answer is 144. write the equation as n-31=113 and add 31 to both sides. the answer is 144.

Ajar contains a mixture of 20 black marbles, 16 red marbles, and 4 white marbles, all the same size. find the probability of drawing a white or red marble on the first draw. 125 12 01 next question ask for turn it in

Math it's appreciated. (picture provided)