m:n = 213:115 = m : n = 73:65
73:65 = 73÷65
mn = 73×56
mn = 3518 = m = 35n18
n : q = 112:113 = 32:43
nq = 32×34
nq = 98 = q = 8n9
q : m = 8n9 : 35n18
qm = 8n9÷35n18
qm = 8n9×1835n
=qm=1635 = q : m = 16 : 35