(2/5) of (2/3) of students = 4/15 of students study French. Then 1-(4/15) = 11/15 of students do not study French. The ratio you want is
(4/15):(11/15) = 4:11
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In a math expression "of" means "times".
If it's a square then sides equal to around 12-13 meters
There are 13 diamonds in a regular deck of cards.
So the probability of picking a diamond card is 13/52.
Is there anything else to this problem?
