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.

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

   96
3. 3.

   After 40% of the students went on a trip, 135 students are left at Noah's school. How many students were at the school before the trip?

   225
4. 4.

   Pia's band had 200 fans. The crowd grew by 20%, then shrank by 10%. How many fans are there at the end?

   216
5. 5.

   Ren's young tree is 60 centimeters tall. It grows by 50%, then a storm trims it by 20%. How tall is the tree at the end?

   72
6. 6.

   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
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.

   Jun's stopwatch is within 3% of the true time. The true time is 60 seconds. What is the smallest time it could show?

   58.2
9. 9.

   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
   • 0.9x
   • 1.2x
   • 1.1x
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?

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