2023 AMC 10A Problems/Problem 3

Revision as of 20:50, 9 November 2023 by Not slay (talk | contribs) (Solution 1)

Problem

How many positive perfect squares less than $2023$ are divisible by $5$?

\[\textbf{(A) } 8 \qquad\textbf{(B) }9 \qquad\textbf{(C) }10 \qquad\textbf{(D) }11 \qquad\textbf{(E) } 12\]

Solution 1

Note that $45^{2}=2025$ so the list is $5,10,15,20,25,30,35,40$ there are $8$ elements so the answer is $\boxed{\textbf{(A) 8}}$.

~zhenghua

Solution 2 (slightly refined)

Since $\left \lfloor{\sqrt{2023}}\right \rfloor = 44$, there are $\left \lfloor{\frac{44}{5}}\right \rfloor = \boxed{\textbf{(A) 8}}$ positive integers.

~not_slay

See Also

2023 AMC 12A (ProblemsAnswer KeyResources)
Preceded by
Problem 2
Followed by
Problem 4
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
All AMC 12 Problems and Solutions
2023 AMC 10A (ProblemsAnswer KeyResources)
Preceded by
Problem 2
Followed by
Problem 4
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
All AMC 10 Problems and Solutions

The problems on this page are copyrighted by the Mathematical Association of America's American Mathematics Competitions. AMC logo.png