Plowing the field

10 farmers $(A,B,\dots ,J)$ are plowing a field.

A and B working together can plow the field in 2 days.
B and C working together can plow the field in 3 days.
C and D working together can plow the field in 5 days.
D and E working together can plow the field in 7 days.
E and F working together can plow the field in 11 days.
F and G working together can plow the field in 13 days.
G and H working together can plow the field in 17 days.
H and I working together can plow the field in 19 days.
I and J working together can plow the field in 23 days.
J working alone can plow the field in 29 days.

How many days does it take if all the farmers are working together?

Answer format: P/Q (Irreductible fraction)