1 giờ có 60 phút nên ta có:
60 : 15 = \(\dfrac{1}{4}\) giờ
60 : 20 = \(\dfrac{1}{3}\)giờ
60 : 30 = \(\dfrac{1}{2}\) giờ
60 : 45 = \(\dfrac{3}{4}\)giờ
60 : 10 = \(\dfrac{1}{6}\) giờ
60 : 5 = \(\dfrac{1}{12}\) giờ
a)\(15'=\dfrac{1}{4}h\)
b) \(20'=\dfrac{1}{3}h\)
c) \(30'=\dfrac{1}{2}h\\ \)
d) \(45'=\dfrac{3}{4}h\)
e) \(10'=\dfrac{1}{6}h\)
f) \(5'=\dfrac{1}{12}h\)
a)\(\dfrac{15}{60}=\dfrac{1}{4}h\)
b)\(\dfrac{20}{60}=\dfrac{1}{3}h\)
c)\(\dfrac{30}{60}=\dfrac{1}{2}h\)
d)\(\dfrac{45}{60}=\dfrac{3}{4}h\)
e)\(\dfrac{10}{60}=\dfrac{1}{6}h\)
f)\(\dfrac{5}{60}=\dfrac{1}{12}h\)
15=1phan 4
20=1phan 3
30=1phan 2
45=3phan 4
10=1phan 5
5=1phan 12
