# Combi-natrics-2

How many subsets $$A$$ of $$\{1,2,3,.....,100\}$$ have the property that no three elements of $$A$$ sum to $$101?$$

Note by Ayush G Rai
2 years ago

MarkdownAppears as
*italics* or _italics_ italics
**bold** or __bold__ bold
- bulleted- list
• bulleted
• list
1. numbered2. list
1. numbered
2. list
Note: you must add a full line of space before and after lists for them to show up correctly
paragraph 1paragraph 2

paragraph 1

paragraph 2

[example link](https://brilliant.org)example link
> This is a quote
This is a quote
    # I indented these lines
# 4 spaces, and now they show
# up as a code block.

print "hello world"
# I indented these lines
# 4 spaces, and now they show
# up as a code block.

print "hello world"
MathAppears as
Remember to wrap math in $$...$$ or $...$ to ensure proper formatting.
2 \times 3 $$2 \times 3$$
2^{34} $$2^{34}$$
a_{i-1} $$a_{i-1}$$
\frac{2}{3} $$\frac{2}{3}$$
\sqrt{2} $$\sqrt{2}$$
\sum_{i=1}^3 $$\sum_{i=1}^3$$
\sin \theta $$\sin \theta$$
\boxed{123} $$\boxed{123}$$

Sort by:

There are 2^10 such subsets. Since 1+2+... + 10 = 55, there is no subset that sums to 101.

Instead of posting each of these problems as individual notes, my suggestion would be for you to post them together in a single note.

Staff - 2 years ago

i have edited the question.try it and also the other two parts of combinatrics.

- 1 year, 11 months ago

good one! i will surely make it in a single note.

- 2 years ago