A hardware supplier manufactures three kinds of clamps, types A, B, and C. Production restrictions force it to make 20 more type C clamps than the total of the other types and twice as many type B clamps as type A clamps. The shop must produce 380 clamps per day. How many of each type are made per day?

Question

anonymous · Answer

A+B+20=C
B=2A
A+B+C=360
solve the three equtions in three unknowns

anonymous · Answer

aww
A+B+C=380

anonymous · Answer

Ok I got 
A=60
B=120
C=200

anonymous · Answer

A+B+C=380
A+B-C=-20
------------
2A+2B=360
B+2B=360
3B=360
B=120

anonymous · Answer

correct :)

anonymous · Answer

Thank you!
that helped me so much