Mr Tham picked twice as many oranges as mangoes from his farm. While sorting out the fruits, he found that only 60% of the fruits are edible. The ratio of the number of edible oranges to the number of edible mangoes was 5:3. There were 90 more edible oranges than edible mangoes.
(a) What was the total number of edible oranges and mangoes?
(b) How many oranges did Mr Than pick at first?