Four words add up to a fifth word numerically:
mars
venus
uranus
saturn
-------- +
neptune
Each of the ten letters (m, a, r, s, v, e, n, u, t, and p) represents a digit in the range 0 up to 9 (equal letters represent equal digits and different letters represent different digits). Furthermore, the digits 1 and 6 are being used most frequently.
Answer:
The easiest way to solve this problem is by writing a computer program that systematically tries all possible mappings from the digits onto the letters. This will give you only one solution which meets the condition that the digits 1 and 6 are most frequently used:
mars m = 4
venus a = 5
uranus r = 9
saturn s = 3
-------- + v = 2 4593
neptune e = 0 20163
n = 1 695163
u = 6 358691
t = 8 -------- +
p = 7 1078610