DAY 15

Comment

This item looks complex but the crucial feature is the comparison between 2/5 and 1/5:
2/5 is larger than 1/5, so dividing by 2/5 gives a smaller result than dividing by 1/5;
infact, 2/5 is twice 1/5, so ... .

Answer

4/23 (or 8/46).

Readers' methods

DG, of Ross on Wye:
I calculated that F is 8/115,
so F divided by 2/5 is the same as 8/115 times 5/2,
which is 40/230 or 4/23.

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