perplexus.info :: Numbers : Counting triplets

Counting triplets (Posted on 2010-03-31)

For how many ordered triplets (a, b, c) of positive integers, each less than 10 is the product abc divisible by 20?

Submitted by Ady TZIDON

Rating: 4.0000 (1 votes)

Solution: (Hide)

ans: 102 See detailed analytical solution + verification by Charlie. Remember what ordered pair (or triplet) stands for.

Comments: ( You must be logged in to post comments.)

Subject	Author	Date
Puzzle Thoughts	K Sengupta	2024-03-11 10:12:53
re: Old dog, new tricks?	Charlie	2010-03-31 17:43:24
Old dog, new tricks?	ed bottemiller	2010-03-31 15:50:35
re: By hand	Charlie	2010-03-31 15:22:09
By hand	Steve Herman	2010-03-31 14:18:25
re: Solution (interpretations)	Jer	2010-03-31 14:09:23
solution	Charlie	2010-03-31 14:06:39
Solution (interpretations)	ed bottemiller	2010-03-31 12:23:44

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