Back to Use proportional relationships to solve multistep ratio and percent problems — Problem 3 · Task Set 5

7.RP.A.3 Tutor Intake -- Multistep Ratio and Percent Problems

This short check helps your tutor see where to start. Work each problem on
your own, without a calculator. If you are not sure, give your best try --
every answer helps your tutor plan your first few sessions.

Grade 7·11 problems·~12 min·Common Core Math - Grade 7·standard·7-rp-a-3

Work through problems with immediate feedback

Concepts

A $100 item increases in price by 20%, and then the new price
decreases by 20%. A student claims the final price is back to
$100 because "+20% and -20% cancel out." Is this correct?

No -- the final price is $96, because the 20% decrease applies to the new price ($120), not the original $100.

Yes -- equal and opposite percents always cancel to return to the original value.

No -- but only because the percents should have been added instead of computed separately.

Yes -- as long as both percents are applied to the same original value.