Difficulty: Extreme!
George bought a bag of 70 lollies on Monday. He didn’t eat many on Monday, but he really liked the flavour. Every day after that he ate three more lollies than he had the previous day. The next Monday, George was about to eat his first lolly for the day and noticed the bag was empty.
How many lollies did George eat on the first Monday?
Scroll down or click for a hint, or the answer!
Brainteaser hint
George ate 70 lollies in 7 days, which is an average of 10 sweets a day. Try making an estimate based on this statistic.
Brainteaser answer
George’s sweet consumption increases at a steady rate, so he would have eaten about 10 sweets on the middle day (Thursday). Monday is three days before Thursday so he would have eaten 3 x 3 = 9 fewer sweets on Monday. That would mean he ate only one sweet!
To check this estimate, George ate:
1 (Monday) + 4 + 7 + 10 (Thursday) + 13 + 16 + 19 (Sunday) = 70 sweets
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