Performance/Efficiency calculation

Question

Hi, I want to calculate following. Instrument A perform 3500 tasks in 1820 minutes while instrument B perform 3500 tasks in 2380 minutes. I want to know as below

1. A has ........ % better then B?
2. B perform -....% lesser than A?
3. What terminology we can use for this % result? Is it efficiency ? Performance? effectiveness or something else?

Answer 1

Instrument A: 3500 tasks/1820 minutes = 1.923 tasks /min

Instrument B: 3500 tasks/2380 minutes = 1.471 tasks/min

Look at the A ratio: (1923 - 1471)/1923 x 100 = 23.5% Instrument A better than Instrument B

Look at the B ratio: (1471-1923)/1471 x 100 = -30.73% Instrument B less than Instrument A

I call it a performance issue!