Weekly Problem 19 - 2013

Stage: 2 and 3 Challenge Level: Challenge Level:1

Old Martha has 5 children, each of whom has 4 children, each of whom has 3 children, each of whom is childless.

How many descendants does Old Martha have?
If you liked this problem, here is an NRICH task which challenges you to use similar mathematical ideas.  

This problem is taken from the UKMT Mathematical Challenges.

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