DAY 77

Comment

One approach is to imagine traveling along the line.
For example, A to B is 2 across, 1 up.
How many across and and how many up is it from B to C ?
Alternatively, you could find a rule for calculating the second number when you know the first number (test your rule on 2 and 2, 4 and 3).

Answer

e = 51.

Readers' methods

George Sharrat, Swimbridge:
The second number is always half the first number plus 1.
half of 100 is 50, plus 1 is 51.

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