3
Problems(2)
3 equal circles,each pass through centers of other 2 (2017 Auckland MO J3)
Source:
12/31/2020
Three equal circles of radius each pass through the centres of the other two.
What is the area of intersection that is common to all the three circles?
geometryequal circles
N = 11...11 divisible by 13 if divisible by 7 (2017 Auckland MO S3)
Source:
11/15/2021
The positive integer , whose decimal representation contains only ones, is divisible by . Prove that this positive integer is also divisible by .
number theorydivisibleDigitsdivides