There are 380 cards kept on a table in a row all facing downward. There are 200 persons to do a task. 1st person flip all the cards so that all cards are facing upward. Then 2nd person flip every 2nd card and so on ith person flip every ith card. This is done by all the 200 persons. How many cards are facing upward at the end ?

Guest Jan 11, 2020

#1**0 **

Not sure if this will work, but I found the GCF of 380 and 200 and divided 380 and 200 by the GCF.

The GCF is 20,

so its really just 19 cards and 10 persons.

Then I found the number of cards facing upward, and multiplied that by 20.]

Probably a really bogus solution.

CalculatorUser Jan 11, 2020