A company produces rectangular advertising boards such that the width is always at least 8 cm shorter than the length, and both the length and width are integers. If the area of a board cannot be more than $320\text{ cm}^2$ and the width is $x$ cm, then find the maximum possible value of $x$.
Solution
✅ Correct Option: 4
Let the width be $x$ cm. Since the length is at least 8 cm more than the width, the smallest possible length is $x+8$ cm. To maximise the width while keeping the area at most $320\text{ cm}^2$, use the minimum allowed length: $x(x+8)\leq320$ For $x=14$, $14\times22=308\leq320$. For $x=15$, $15\times23=345>320$. The maximum possible integer width is $14$ cm.
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