A hardware supplier manufactures three kinds of clamps, types A, B, and C. Production

restrictions force it to make 10 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 250 clamps per day.
How many of each type are made per day?

How many type A clamps are produced?
How many type B clamps are produced?
How many type C clamps are produced?

1 answer

a+b+c = 250
c = 10 + (a+b)
b = 2a

rearrange things a bit:

a + b + c = 250
-a - b + c = 10
-2a + b = 0

add the top two to get
2c = 260
c = 130

a+b-130 = -10
a+2a-130 = -10
3a = 120
a = 40
b = 80