a) 11:40 − 8:15 =
[R]

b) 12:21 − 9:16 =
[R]

c) 4:17 − 2:33 =
[R]

d) 6:12 − 3:17 =
[R]

e) 2:51 − 1:03 =
[R]

f) 12:06 − 10:24 =
[R]

g) 6:16 − 3:33 =
[R]

h) 10:38 − 8:02 =
[R]

i) 10:25 − 7:32 =
[R]

j) 10:10 − 8:08 =
[R]