A Linear Programming Problem Has Three Constraints, Plus Nonnegativity Constraints

Multiple Choice

A linear programming problem has three constraints, plus nonnegativity constraints on X and Y. The constraints are: 2X + 10Y ≤ 100; 4X + 6Y ≤ 100; 6X + 3Y ≥ 90. What is the largest quantity of X that can be made without violating any of these constraints?

A) 50
B) 30
C) 25
D) 15
E) 10