Answer:
for the first question, the answer is B
6 × 6 (faces of a dice) = 36, there are 6 way to add 1-6 to 7 (1+6, 2+5, 3+4), so the answer is 6/36 or simplified into 1/6
for the second question, the answer is B
3/4 = 15/20, 3/5 = 12/20 (least common multiple is 20)
15/20 - 12/20 = 3/20