Maths

1)A company decides to produce a batch of electronic photo-frames. If the job is to be done by Factory A, 15 days are required. But it takes only 10days by Factory B .It is known that Factory A and Factory B together can produce 1250 electronic photo-frame each day.
a)Find the number of electronic photo-frame produced in the batch.
2)A bus leaves the bus terminal. When it come to the first stop ,1/3 of the passengers get off the bus and 16 passengers get on. If the number of passengers on th bus now only 3/4 of that when the bus left the bus terminal, find the number of passengers that were on the bus when it left the bus terminal.
Please use equation to find the answer!!!