1. 30 / 70 = 3 / 7
2. 30= 2·3·5
70 = 2·5·7
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cmmdc= 2·5=10
cmmmc= 2·3·5·7= 210
3. 950= 2··5² ·19
D₉₅₀ = { 1,2,10,19,25,38,50,95,190,475,950 }
a/b = 27/81 = 1/3
27 = p%·81
27 :81 = p%
p% = 1:3 = 0,33 = 33/100 = 33 %
30% ·120 = 30 /100 ·120 = 3600 / 100 = 36
a/30 = 0,1 /b
ab = 3
