Answer:
y = 2
Explanation:
PQ is a diameter, so arc PQ has a central angle of 180°. Inscribed angle PRQ has a measure half that, or 90°. (An inscribed triangle with one side a diameter is a right triangle.)
Then you can write ...
53y -16 = 90
53y = 106 . . . . . add 16
y = 106/53 = 2 . . . . divide by the coefficient of y
y = 2