10mn
To simplify the expression (7m \cdot 6n - 5m \cdot 8n), first multiply the coefficients: (7 \cdot 6 = 42) and (5 \cdot 8 = 40). This gives us (42mn - 40mn). Now, combine like terms: (42mn - 40mn = 2mn). Thus, the simplified expression is (2mn).
The time required to administer 200ml of glucose IV solution would depend on the rate of administration, typically measured in ml per hour. For example, if the rate is set at 100ml per hour, then administering 200ml would take 2 hours.