30%=30/100=0.3
60+30%=60+0.3=60.3
to obtain 78, hmm
60+18=78
18/60=3/10=30%
what you mean is
find what the value is when you take 30% of 60 and add it to the original number
30% of 60
percent mean sparts out of 100
30%=30/100=0.3
'of' means multiply
30% of 60 means 0.3 times 60 or 18
so
60+30% of 60=60+18=78
hope this is what you were looking for