exactly one of the following numbers cannot be written as a^3+b^3

a>700056
b>707713
c>7000639
d>7077283
e>7077915

• when a^3 divided by 7 it can give remaider either 0,1 or 6(a is any natural no)
  so when a^3+b^3 divide by 7 it can give remaider 0,1,2,4,6,7
  7077283 gives remainder 3 when divided by 7. so it cant be represent in this equetion.
  
• 11 years agoHelpfull: Yes(0) No(0)