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Problems Archives

  • Problem 680 will be accessible in 19 hours, 4 minutes (Sunday, 22nd September 2019, 04:00 am)

The problems archives table shows problems 1 to 669. If you would like to tackle the 10 most recently published problems then go to Recent problems.
Click the description/title of the problem to view details and submit your answer.


IDDescription / TitleSolved By
101Optimum polynomial
9936
102Triangle containment
19584
103Special subset sums: optimum
6938
104Pandigital Fibonacci ends
14478
105Special subset sums: testing
6934
106Special subset sums: meta-testing
5523
107Minimal network
9713
108Diophantine reciprocals I
11307
109Darts
7088
110Diophantine reciprocals II
7125
111Primes with runs
6261
112Bouncy numbers
22152
113Non-bouncy numbers
9826
114Counting block combinations I
9579
115Counting block combinations II
8746
116Red, green or blue tiles
10737
117Red, green, and blue tiles
9841
118Pandigital prime sets
5984
119Digit power sum
10955
120Square remainders
12365
121Disc game prize fund
8572
122Efficient exponentiation
6810
123Prime square remainders
10283
124Ordered radicals
12320
125Palindromic sums
12096
126Cuboid layers
4046
127abc-hits
5401
128Hexagonal tile differences
4306
129Repunit divisibility
5485
130Composites with prime repunit property
5162
131Prime cube partnership
6452
132Large repunit factors
5540
133Repunit nonfactors
4800
134Prime pair connection
6104
135Same differences
5563
136Singleton difference
4870
137Fibonacci golden nuggets
4722
138Special isosceles triangles
5048
139Pythagorean tiles
4877
140Modified Fibonacci golden nuggets
3697
141Investigating progressive numbers, n, which are also square
3326
142Perfect Square Collection
5076
143Investigating the Torricelli point of a triangle
2306
144Investigating multiple reflections of a laser beam
5420
145How many reversible numbers are there below one-billion?
14919
146Investigating a Prime Pattern
4324
147Rectangles in cross-hatched grids
2581
148Exploring Pascal's triangle
4452
149Searching for a maximum-sum subsequence
4208
150Searching a triangular array for a sub-triangle having minimum-sum
3432