5
reason is because if you’re pentagon has lines of 5 then the area would be 25
If you paid attention in math, you would know this lol jk.
But you would rewrite it as 5+4
I suspect you meant
"How many numbers between 1 and 100 (inclusive) are divisible by 10 or 7?"
• Count the multiples of 10:
⌊100/10⌋ = ⌊10⌋ = 10
• Count the multiples of 7:
⌊100/7⌋ ≈ ⌊14.2857⌋ = 14
• Count the multiples of the LCM of 7 and 10. These numbers are coprime, so LCM(7, 10) = 7•10 = 70, and
⌊100/70⌋ ≈ ⌊1.42857⌋ = 1
(where ⌊<em>x</em>⌋ denotes the "floor" of <em>x</em>, meaning the largest integer that is smaller than <em>x</em>)
Then using the inclusion/exclusion principle, there are
10 + 14 - 1 = 23
numbers in the range 1-100 that are divisible by 10 or 7. In other words, add up the multiples of both 10 and 7, then subtract the common multiples, which are multiples of the LCM.
There are 10 digits possible for each of the 4 places .
So the number of digits possible is 10^4 = 10,000
