According to Unwin's formula, the relation between the diameter of rivet hole (d) and the thickness of plate (t) is given by (where d and t are in mm)
A. $${\text{d}} = \sqrt {\text{t}} $$
B. $${\text{d}} = 1.6\sqrt {\text{t}} $$
C. $${\text{d}} = 2\sqrt {\text{t}} $$
D. $${\text{d}} = 6\sqrt {\text{t}} $$
Answer: Option D
It's d=6√t