If P and Q represent two towns 48 kms apart, and if A is walking from P to Q at 7 km/hr while B walks from Q to P at 5 km/hr, both starting at 9:00 am, at what time will they be 12 km apart?
Answer: 12 noon and 2 pm
case I:
48 - (7t + 5t) = 12
or t = 3
so, time = 9 + 3 = 12 hours
case II
5t - 12 + 7t = 48
or, t = 5 hours
SO time = 2 pm
Answer: 12 noon and 2 pm
case I:
48 - (7t + 5t) = 12
or t = 3
so, time = 9 + 3 = 12 hours
case II
5t - 12 + 7t = 48
or, t = 5 hours
SO time = 2 pm
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