Question 525968
S[500]=500/2(1+500)=250*501=125,250 Sum of all the numbers
S[100]=100/2(5+500]=50*505=25250 Sum of all the numbers divisible by 5.
125250-25250=100,000 the sum of all the numbers from 1 to 500 that are NOT divisible by 5.
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Ed