Two machines together produce a total of 2015 pieces. Machine A operates for 6 1/2 hours and produces an average of 170 pieces per hour. Machine B operates

Question

Two machines together produce a total of 2015 pieces. Machine A operates for 6 1/2 hours and produces an average of 170 pieces per hour. Machine B operates For 7 hours. What percent of the average hourly production of machine A is the average hourly production of machine B?

Answer 1

Let's try this.

 

We know that the total number of pieces made is 2015, so

 

MachineA_rate * MachineA_time + MachineB_rate * MachineB_time = 2015.

 

We know MachineA_rate = 170, MachineA_time = 6.5 hours, and MachineB_time = 7 hours. We want to calculate MachineB_rate. Let's plug and chug.

 

170 pieces/hour * 6.5 hours + MachineB_rate * 7 hours = 2015 pieces

1105 pieces + MachineB_rate * 7 hours = 2015 pieces

 

Subtract 1105 from both sides.

 

MachineB_rate * 7 hours = 910 pieces

MachineB_rate = 910 pieces / 7 hours

MachineB_rate = 130 pieces/hour

 

Now we need to find the percentage of MachineB_rate to MachineA_rate.

 

MachineB_rate / MachineA_rate * 100%, plug and chug

 

(130pieces/hour) / (170pieces/hour) * 100% = approximately 76.4%