(a) \(3\frac{4}{9} \div (5\frac{1}{3} - 2\frac{3}{4}) + 5\frac{9}{10}\)
\(\frac{31}{9} \div (\frac{16}{3} - \frac{11}{4}) + \frac{59}{10}\)
\(\frac{31}{9} \div (\frac{64 - 33}{12}) + \frac{59}{10}\)
\((\frac{31}{9} \div \frac{31}{12}) + \frac{59}{10}\)
\((\frac{31}{9} \times \frac{12}{31}) + \frac{59}{10}\)
\(\frac{12}{9} + \frac{59}{10} = \frac{120 + 531}{90}\)
\(\frac{651}{90} = \frac{217}{30}\).
(b)

+	1	3	5
2	3	5	7
3	4	6	8
4	5	7	9

Let E be the event of the sum being greater than 3 and less than 7 and S be the total sample space.
n(E) = 4; and n(S) = 9.
P(E) = \(\frac{n(E)}{n(S)} = \frac{4}{9}\)