Problem
COM-B2-M02-P002 Divisible by \(3\) or \(5\)
#2
★★☆☆☆ Level 2 of 5
How many integers from \(1\) to \(200\) are divisible by \(3\) or by \(5\)?
Do not forget the numbers divisible by \(15\).
There are \(\left\lfloor\frac{200}{3}\right\rfloor=66\) multiples of \(3\), and \(40\) multiples of \(5\). Multiples of both, i.e. of \(15\), number \(13\). The answer is \(66+40-13=93\).
A good short problem on intersecting conditions.