Problem:
The length of the interval of solutions of the inequality a≤2x+3≤b is 10. What is b−a?
Answer Choices:
A. 6
B. 10
C. 15
D. 20
E. 30
Solution:
The solution of the inequality is
2a−3​≤x≤2b−3​
If 2b−3​−2a−3​=10, then b−a=(D)20​.
The problems on this page are the property of the MAA's American Mathematics Competitions