Your store cashiers have an average time of 110 seconds to process a sales transaction. Cashier A is 20% faster than
average. How many seconds will it take cashier A to process a customer?

88 seconds.

You are calculating a 20% decrease. This means you need to calculate 20% of 110.

First, calculate 10%, which is much easier. To do this, divide 110 by 10 (because you’re going from 100% to 10%, which is a division by 10, so you need to do the same to the 110)

110/10 = 11

However, now you need to get from 10% to 20%, so multiply by 2.

20% = 22

HOWEVER, YOU’RE NOT DONE HERE.

I know too many people who make the mistake in an exam of stopping here, myself included.

You’re working out a decrease! This is only the amount it has decreased by, not the final time.

To calculate the final time, you need to minus our value from the average.

So, 110-22 = 88

Therefore, it takes cashier A 88 seconds!

Hope this helps :)