0
0
0.25 multiplyed by 2 = 0.5 multiplyed by pi =1.57
60
because prime numbers have to be multiplyed by 1 and itself for example 17 it can only be multiplyed by 1 and itself.
30
o ....anthing multiplyed or divided by o is o
80
1/2 or .5
37 and 3/8
5, 7 and 11
90
They are: 2*5*13 = 130