13:21
13/169 = 1/13
13/100
It is 13/46.
The equivalent ratio is: 22 to 26
You've described only one ratio. The ratio is (7pencils) / (13 erasers) = 0.5385 pencil per eraser (rounded)
13/27 which cannot be simplified.
Divide 6 by 13.
11/13 = 0.8462 (approx).
It is 16/13 which cannot be simplified.
Yes, there is a bronze ratio: (3 + sqrt(13)) / 2.
13 to 10