Answer
Together, they have 99 marbles.
Explanation
Ravi has 33 marbles.
His brother has twice (two times) as many marbles as him. Ravi's brother has 33×2=66 marbles.
Together, they have 33+66=99 marbles.
32 people each get a pint and 1 pint is roughly 0.125 gallons so assuming that the pitcher can hold one gallon each then it would be 4 pitchers D is your answer.