Answer:
a) Let x be the number of bags of snacks supplied, and y be the number of beverages supplied.
b) We know that the total number of items supplied is the sum of the number of bags of snacks and the number of beverages, so we can write:
x + y = 400
We also know that the number of beverages supplied is 50 more than the number of bags of snacks, so we can write:
y = x + 50
Therefore, the system of equations for the situation is:
x + y = 400
y = x + 50