given:
total order placed for a : 110 units.
currently available units of a : 60 units.
4 units of b required for each a
current available units of b =20
solution:
remaining a to be produced= 110-60= 50 units
so, units of b required =50*4=200 units.
remaining units of b required=200-20=180 units.
net requirements for b= 180 units.