cryptarithmetic Problem
SEND
+MORE
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MONEY
Let the numbers "to carry" be t, u, v, and w that I've written above
the addition: tuvw SEND +MQRE ----- MQNEY The numbers "to carry" are either 0 or 1. Since the letter O looks like the digit 0 (zero), I will use Q instead to avoid confusion. Obviously t = M = 1, so we have 1uvw SEND +1QRE ----- 1QNEY Case 1: u=1 11vw SEND +1QRE ----- 1QNEY Then S = 8, Q = 9 11vw 8END +10RE ----- 10NEY This makes v=1 to prevent E=N But in order to cause a carry of 1, E could only be 9, causing N=0 but Q is already 0. That rules out case u=1. So u=0 10vw SEND +1QRE ----- 1QNEY so S=9, Q=0 10vw 9END +10RE ----- 10NEY v=1 to prevent E=N 101w 9END +10RE ----- 10NEY E + 1 = N w + N + R = 10 + E D + E = Y + 10w Try w=0 E + 1 = N N + R = 10 + E D + E = Y Substitute E + 1 for N in the second equation E + 1 + R = 10 + E That simplifies to R = 9 But S = 9, so w = 1 1011 9END +10RE ----- 10NEY N + R = E + 9 1 + E = N D + E = Y + 10 Substitute 1 + E for N in the 1st equation 1 + E + R = E + 9 R = 8 1011 9END +108E ----- 10NEY E + 1 = N D + E = Y + 10 0 and 1 are used, so Y > 1, so D + E > 11 So the only possibility is {D,E} = {6,7} or {D,E} = {5,7} Try {D,E} = {6,7} So Y = 3 1011 9END +108E ----- 10NE3 But E has to be 1 more than E E can't be 7 because that would make N=8=R. E can't be 6 because that would make N and D both be 7. So {D,E} = {5,7} which makes Y = 2 1011 9END +108E ----- 10NE2 Since N is 1 more than E, E can't be 7, for that would make N=8=R, so E=5, and D=7 1011 95N7 +1085 ----- 10N52 So N=6
SOLUTION 1011 9567 +1085 ----- 10652