The thing to notice here is that every even number has a 2 in it. You can pull all these…
[latexpage] The function f is defined for each positive three-digit integer n by $f(n) = 2^x 3^y 5^z$, where x,…
Look at what you're trying to do: reduce the amount of ash by reducing the number of truckloads. Fewer truckloads…
This is rated hard. Why? Mostly it's picking what to do quickly. First eliminate the mixed numbers, then cancel the…
The question you want to ask yourself--no matter how weird it sounds on the surface--is this: does swimming cause asthma,…
Just focus on how many zeros there are after the 1. That's 50, so 51 digits. Subtract the 74 and…
Survivorship bias is when you make a judgement based on surviving examples only. "Music was better in the 1960s." Maybe,…
A couple decides to have 4 children. If they succeed... Find the number of ways to select "exactly two boys…