The sum of prime numbers upto 75 is:
712
Prime numbers up to 75: 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73 (21 primes).
Sum in groups: 2 + 3 + 5 + 7 = 17; 11 + 13 + 17 + 19 = 60; 23 + 29 + 31 + 37 = 120.
41 + 43 + 47 + 53 = 184; 59 + 61 + 67 = 187; 71 + 73 = 144.
Total = 17 + 60 + 120 + 184 + 187 + 144 = 712.
Hence, the sum of prime numbers up to 75 is 712.
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