Japan | A Nice Olympiads Trick | No Calculator Allowed | 2^30 - 1

[@sie_khoentjoeng4886]

Fortunately, I remember some popular 2 power n, ie. 2^8 = 256 (8-bit) 2^10 = 1024 (1kbyte) 2^16 = 65.536 (16-bit) 2^24 = 16.777.216 (RGB color, 24-bit).. I just multioly by 2^6 (=64) and substrat by 1. 2^30 - 1 = 2^24 x 2^6 - 1 = 16.77.216 x 64 - 1

[@billy.7113]

1024³ - 1

[@nathanmattor401]

So the answer comes from some long arithmetic crank? How disappointing! Olympiad problems are supposed to have some clever trick that makes the answer easy.