a) 4:31 − 2:21 =
[R]

b) 6:02 − 2:34 =
[R]

c) 6:07 − 4:14 =
[R]

d) 6:24 − 3:20 =
[R]

e) 12:36 − 10:03 =
[R]

f) 8:05 − 4:35 =
[R]

g) 4:15 − 2:30 =
[R]

h) 6:03 − 2:20 =
[R]

i) 7:00 − 4:09 =
[R]

j) 12:30 − 10:20 =
[R]