Dividing 151001 by 11^4 give quotient 10 and remainder 4591 So 151001 = 10*11^4 + 4591 Dividing 4591 by 11^3 gives quotient 3 and remainder 598 So 151001 = 10*11^4 + 3*11^3 + 598 Dividing 598 by 11^2 gives quotient 4 and remainder 114 So 151001 = 10*11^4 + 3*11^3 + 4*11^2 + 114 Dividing 114 by 11 gives quotient 10 and remainder 4 So 151001 = 10*11^4 + 3*11^3 + 4*11^2 + 10*11 + 4 So v=10, w=3, x=4, y=10, z=4 is ONE solution. But is that the only one? We will show that it indeed is the only solution: --------------------------------------------------- So we show that that is the ONLY solution. v cannot be larger than 10. Suppose that v could be less than 10, then the largest v(11^4)+w(11^3)+x(11^2)+y(11)+z could possibly be would be when v=9, w=10, x=10, y=10, z=10 9(11^4)+10(11^3)+10(11^2)+10(11)+10 = 146409 But that is less than 151001. So v can only be 10. So we know that: 10(11^4)+w(11^3)+x(11^2)+y(11)+z=151001 146410+w(11^3)+x(11^2)+y(11)+z=151001 w(11^3)+x(11^2)+y(11)+z=4591 If w were more than 3, the smallest w(11^3)+x(11^2)+y(11)+z could be is when w=4,x=0,y=0,z=0 4(11^3)+0(11^2)+0(11)+0 = 5324 But that is larger than 4591, so w is not greater than 4. On the other hand, If w were less than 3, the largest w(11^3)+x(11^2)+y(11)+z could be is when w=2,x=10,y=10,z=10 2(11^3)+10(11^2)+10(11)+10 = 3992 But that is smaller than 4591, so w is not less than 3 either. Therefore w = 3 is the only possibility, and 3(11^3)+x(11^2)+y(11)+z = 4591 x(11^2)+y(11)+z = 598 If x were more than 4, the smallest x(11^2)+y(11)+z could be is when x=5,y=0,z=0 5(11^2)+0(11)+0 = 605 But that is larger than 598, so w is not greater than 4. On the other hand, If x were less than 4, the largest x(11^2)+y(11)+z could be is when x=3,y=10,z=10 3(11^2)+10(11)+10 = 483 But that is smaller than 598, so x is not less than 4 either. Therefore x = 4 is the only possibility, and 4(11^2)+y(11)+z = 598 y(11)+z = 114 Y cannot be more than 10. If y were less than 10, the largest y(11)+z could be is when y=9,z=10 9(11)+10 = 109 But that is smaller than 114, so x = 10. So we have proved that v=10, w=3, x=4, y=10, z=4 is the only solution. Edwin