SAT Mathematics Practice Test 6

To find the percent increase of the customer’s water bill, the absolute increase of the bill, in dollars, is divided by the original amount of the bill, and the result is multiplied by 100%, as follows:
Choice A is incorrect. This choice is the difference $79.86-75.74$ rounded to the nearest tenth,which is the (absolute) increase of the bill’s amount, not its percent increase. Choice B isincorrect and may be the result of some calculation errors. Choice C is incorrect and is theresult of dividing the difference between the two bill amounts by the new bill amount instead of the original bill amount.