Question

Electric saw A cuts planks at a uniform rate of 150 every 30 seconds, and Electric saw B cuts planks at a uniform rate of 130 every 13 second. Of the 2 saws run simultaneously, how many seconds will take for them to produce a total of 225 planks

Answer 1

Saw A = 150 planks/30 seconds = 5 planks per second

Saw B = 130 planks/ 13 seconds = 10 planks per seconds

5 + 10 = 15 planks per second total

225 planks / 15 planks per second = 15 seconds

Answer: 15 seconds