IMC 2019 Q10
10. A recent report about the amount of plastic created in the last 65 years stated that the 8.3 billion tonnes produced is as heavy as 25 000 Empire State Buildings in New York or a billion elephants.
On that basis, how many elephants have the same total weight as the Empire State Building?
- A 4000
- B 40 000
- C 400 000
- D 4 000 000
- E 40 000 000
Intermediate Mathematical Challenge 2019, Question 10. © UK Mathematics Trust. Original paper on ukmt.org.uk
Answer: B 40 000
We are told that the weight of 25 000 Empire State Buildings is equal to the weight of one billion elephants. So the Empire State Building weighs the same as \(\dfrac{1\,000\,000\,000}{25\,000}\) elephants = \(\dfrac{1\,000\,000}{25}\) elephants = 40 000 elephants.
Solution © UK Mathematics Trust, from the IMC 2019 solutions. Longer versions with investigations: Solutions and investigations (PDF).