The rules of this problem will be as follow:
we have a * b = x
1) If a > 1 and b > 1 ⇒⇒⇒ x > a and x > b
2) If a > 1 and b < 1 ⇒⇒⇒ x < a and x > b
3) If a < 1 and b < 1 ⇒⇒⇒ x < a and x < b
4) If a = 1 and b > 1 ⇒⇒⇒ x > a and x = b
5) If a = 1 and b < 1 ⇒⇒⇒ x < a and x = b
=================================================
2a) (13/4) * (5/8) = x ⇒⇒⇒⇒ rule (2)
∴ x < (13/4) and x > (5/8)
2b) (4/3) * 6 = x ⇒⇒⇒ rule (1)
∴ x > (4/3) and x > 6
2c) (2/5) * (1/7) = x ⇒⇒⇒⇒ rule (3)
∴ x < (2/5) and x < (1/7)
2d) (5/8) * (7/7) = x ⇒⇒⇒ rule (5)
x = (5/8) and x < (7/7)