Consider all positive integers between 3000 and 4000 which, when divided by any of the first three primes, leave a remainder of 1.
Find the sum of all these integers.
(3000+x) mod 2 = 1 therefore x is odd
(3000+x)mod 3=1
so
(3000+x) mod6 =1
(3000+x)mod5 =1
so
(3000+x)mod30=1
The smallest number that meets this requirement is x=1
the next is x=31,
then it goes up by 30.
The numbers will be
3000(1+31+61+ ........ 991)
Sum=3000*34+(1+(1+30)+(1+2*30)+ ........ (1+33*30))
Consider the AP a=1, d=30, n=34,
\(\qquad S_{n}=\frac{n}{2}(a+L)\\ \qquad S_{34}=\frac{34}{2}(1+991)\\ \qquad S_{34}=17*(992)\\ \qquad S_{34}=16864\\\)
Sum= 3000*34+16864 = 118864
I have just reapaired my formulas in red. Now the answers to this interpretation of the question are the same.