a) \(3h\;30ph\) \(= \displaystyle 3{{30} \over {60}}h = 3{5 \over {10}}h = 3,5h;\)
b) \(2h\;15ph\) \(= \displaystyle 2{{15} \over {60}}h = 2{1 \over 4}h = 2{{25} \over {100}}h \)\(= 2,25h;\)
c) \(0h\;45ph\) \(\displaystyle = {{45} \over {60}}h = {3 \over 4}h = {{75} \over {100}}h\)\( = 0,75h;\)
d) \(6h\;12ph\) \(\displaystyle = 6{{12} \over {60}}h = 6{2 \over {10}}h = 6,2h.\)
