(i) The given digits are 3, 7, 2 and 5
(a) 7532 is the greatest 4-digit number
(b) 2357 is the smallest 4-digit number
(ii) The given digits are 6, 1, 4 and 9
(a) 9641 is the greatest 4-digit number
(b) 1469 is the smallest 4-digit number
(iii) The given digits are 7, 0, 4 and 2
(a) 7420 is the greatest 4-digit number
(b) 2047 is the smallest 4-digit number