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The answers are - a = 13, b = 7, c = 29, d = 45, e = 107.
The number in the upper block equals the sum between the numbers in the two blocks below it. For example,
205 = 98 + 107(e);
98 = 45(d) + 53;
107(e) = 53 + 54,
etc.

Bingo...!