Write down the first n primes.
Erase one of them and the mean of the remaining numbers is 10.
What number did you erase?
We erase 7, which is the 4th prime, from a sequence of numbers consisting of the first 8 primes to obtain the desired result as follows:
The sequence - 2, 3, 5,11, 13, 17, 19
sums to 70 and, therefore has the mean 70/7=10
* Looking for an analytical explanation of my own and will posit it when the same is found and discerned to the fullest possible extent.
Edited on May 26, 2022, 10:30 pm
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