Question

determinati 11 numere impare consecutive stiind ca daca, din suma lor scadem suma numerelor pare cuprinse intre ele, atunci obtinem 2027.

Answer 1

a+a+2+a+4+a+6+a+8+a+10+a+12+a+14+a+16+a+18+a+20 - a-1-a-3-a-5-a-7-a-9 -a-11-a-13-a-15-a-17-a-19 =2027
2+4+6+8+10+12+14+16+18+a +20 - 100 =2027
110 +a -100 =2027
10+a=2027
a=2027-10
a=2017
a+2 = 2019
a+4 = 2021
si tot asa 
cele 11numere impare sunt :
2017;2019;2021;2023;2025;2027;2029;2031;2033;2035;2037
cele 10 numere pare intre ele sunt :
2018;2020;2022;2024;2026;2028;2030;2032;2034;2036
am facut proba, nr. imp - nr.par si da :
22.297-20270 = 2027