if an iv dose of mannitol is 1.5g/kg,administrated as 15% solution.how many mls of the solution should be administered to 150 pound patient

1 kg = 2.2046 lbs.

So a 150 pound patient weighs 150/2.2046 kg. = 68 kg.

The IV dose is therefore
= 1.5 g/kg * 68 kg
= 106 g

In a 15% solution, volume
= 106 g / (0.15 g/ml)
= 707 ml.