Question 203 of 347MediumNUMERICAL
3×722+2×1022−44 when divided by 18 leaves the remainder
Answer: 15 Solutions · 1
Official solution
\[3\times7^{22}+2\times10^{22}-44 = 3(6+1)^{22}+2(9+1)^{22}-44\]
(1+6)22=1+6λ and (1+9)22=1+9μ for integers λ,μ (all higher terms carry factors of 6, 9 respectively).
\[=3(1+6\lambda)+2(1+9\mu)-44=18\lambda+3+18\mu+2-44=18\delta-39=18\delta'+15\]
Remainder = 15 Answer the question to unlock