Budgeting

Dear Sir, J Co makes a component M which uses 3 kg of raw material X. The opening inventory at the start of next year is expected as follows. Opening inventory of raw material X 5,000 kg @ $4 Opening inventory of component M 3,000 units Budgeted sales of component M are expected 48,000 units (occurring evenly throughout they year). Closing inventory at the end of the year is as follows. Closing inventory of raw material X One month's worth of production Closing inventory of component M Two month's worth of sales What is the material purchases budget for the year? Material purchase = material required - opening inventory + closing inventory I can calculate the material required (159,000 kg) and opening inventory (5,000 kg) is given but i don't know how to calculate the closing inventory. Please explain how to calculate the closing inventory for this. Thank you.