Problem 22 · 2016 Math Kangaroo
Stretch
Arithmetic & Operations
Eva writes seven numbers on a piece of paper, one of which is 201. She adds up these seven numbers and gets 2016. Now she replaces the 201 with the number 102 and again adds up the seven numbers. Which result does she get now?
Show answer
Answer: C — 1917
Show hints
Hint 1 of 2
Only one number changes, so only the change in that number changes the total.
Still stuck? Show hint 2 →
Hint 2 of 2
Find how much smaller 102 is than 201, and subtract that from 2016.
Show solution
Approach: adjust the sum by the change in the single number
- Replacing 201 with 102 lowers that number by 201 − 102 = 99.
- The total drops by the same 99: 2016 − 99 = 1917.
Mark:
· log in to save