Simplify:
(i) 2 1/4 ÷ 2/7 of 1 1/3 x 2/3
(ii) (3/7 ÷ 1/2) of 1 1/7
(iii) (1 7/8 ÷ 1 1/2) of (8 1/3 ÷ 1 1/2)
(iv) 1/3 of 60 ÷ 60
