composite number means a number that can be formed by multiplying two smaller numbers
3n-1 for n=2, 3n-1=3*2-1=6-1=5
3n-1 for n=10, 3n-1=3*10-1=30-1=29
5 is composite because 2*2.5=5
29 is composite because 5*5.8=29
3 151/990
I think I really hopes this and i need at least like 20 characters so just ignore this

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From there you can cross multiply to get rid of the denominators.
4e=2x20
4e=40
e=10
There would be 10 ears.
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