Mary and Joseph had a total of 450 sea shells.

Mary gave `2/5`of her sea shells to Bella and Joseph lost 70 sea shells.

In the end, the ratio of the number of Mary's sea shells to that of Joseph became 1:5.

(a) Find the number of sea shells that Joseph had in the beginning.

(b) If twice the number of what Joseph had at first is equal to 5 times the number of Ann's shells, find the number of shells that Ann has.

Notes to students:

1. If the question above has parts, (e.g. (a) and (b)), given that the answer for part (a) is 10 and the answer for part (b) is 12, give your answer as:10,12
2. If your answer is a ratio, leave it as a:b