How many of each type of switch were made?

Question

An electronics company makes two types of switches. Type A takes 3 minutes to make and requires ​$2 worth of materials. Type B takes 6 minutes to make and requires ​$6 of materials. In the latest production​ batch, it took 36 hours to make these​ switches, and the materials cost ​$1960. How many of each type of switch were​ made?

Answer 1

3a +6b = 60(36) minutes

2a +6b = 1960 dollars

subtract 2nd equation from 1st to eliminate one variable

a = 60(36) - 1960 =200 Type A switches

6b = 1960 - 400 = 1560

b = 1560/6 = 260 Type B switches

or just graph the two equations and find the intersection point (a,b) = (200 260)