13+115+135+163+199+1143=______ .

13+115+135+163+199+1143=______ .

13 + 115 + 135 + 163 + 199 + 1143, = [(1-13) + (13-15) + (15-17) + (17-19) + (19-111) + (111-113)] × 12, = [1-113] × 12, = 1213 × 12, = 613; so the answer is: 613