I have a question in a tutorial, one of these that give the answers in brackets. However, I think the answer given may be wrong. Anyone check this please, if the given answer is correct, how is it worked out.

Question

I have a question in a tutorial, one of these that give the answers in brackets. However, I think the answer given may be wrong. Anyone check this please, if the given answer is correct, how is it worked out. 
Q A centrifugal pump is required to lift 400 kg of water per second to a height of 6 m. The efficiency of the pump is 60%. Determine the power supplied to the pump. 
The answer given is 29.23 kW, I am getting 39.23 kW.

Power*.6=400*g*6

It is a typo in the answer key.

Thanks for that.