Answer:
D. 60
Step-by-step explanation:
Since the question stated that the number of marbles given out to his 6 friends were equal, we are certain that the total number of marbles is a factor or multiple of 6.
The only other assumption here is the number of marbles given has to be whole number. This means we just have to go through the answer choices and pick the one that is a multiple of 6.
A. 15 - This is wrong as 15 is not a multiple of 6.
B. 33 - This is wrong as 33 is not a multiple of 6.
C. 56 - This is wrong as 56 is not a multiple of 6.
D. 60 - This is CORRECT as 60 is a multiple of 6.
If Jorge gives each of his friends 10 marbles each, it would bring the total number of marbles to be 60.
, we get 
and 
, so we can parameterize the intersection by
.
