Percent increase, percent decrease and percent error

Answer Key - Grade 7 Math Worksheet - Challenge Me

Circle the best answer, or write your answer on the line.

1. 1.

   Kira's school library now has 220 books, after the number of books grew by 10%. How many books did it have before?

   200
2. 2.

   After 20% of its trees were cut down, Luz's park has 140 trees left. How many trees did the park have before?

   175
3. 3.

   Milo's bucket has 72 liters of water left after 25% leaked out. How many liters did the bucket hold before?

   96
4. 4.

   Tala's class has 150 pizza slices. 20% get eaten, then a delivery adds 50% more than what is left. How many slices are there at the end?

   180
5. 5.

   Zee's orchard had 400 apples. Picking day brought 10% more apples, then wind took 10% of all of them. How many apples are there at the end?

   396
6. 6.

   Bo's measuring jug is within 4% of the true amount. The true amount is 500 milliliters. What is the smallest amount the jug could show?

   480
7. 7.

   Esme's step counter is within 5% of the true count. The true count is 8000 steps. What is the largest count it could show?

   8400
8. 8.

   Kira's plant shop starts with x plants. The number of plants goes up by 20%, then down by 10%. Which expression gives the final number of plants?

   • 1.08x
   • 1.2x
   • 0.9x
   • 1.1x
9. 9.

   x is the number of bikes at Luz's school on Monday. By Tuesday the number goes down by 10%, then up by 30%. Which expression gives the number on Wednesday?

   • 1.2x
   • 1.17x
   • 0.9x
   • 1.3x
10. 10.

    x is the number of pages Milo read on day one. The next days it goes up by 40%, then down by 30%. Which expression gives the final number of pages?

    • 0.98x
    • 0.7x
    • 1.4x
    • 1.1x