hmm
tr some
m=3
n=4
p=5
q=6
A=m/q=3/6=1/2=0.5
B=n/p=4/5=0.8
test
first,
A+B, andB is irrational
hmm, B is not irrational and the result is not irrational
2nd
0.5+0.8=1.3, it is rational
3rd the fraction is wrong
m/q times n/p=(mn)/(qp) so this is wrong
4th, fraction is also wrong (but it is true that produce of 2 rationals makes rational)
pick 2nd from top
