Tramont co (BPP question 54 )

Hi sir I have done question 54 BPP KIT (tramont co ). For the NPV calculation the examiner has deduct capital allowances before charging tax ,but he has not added it back after charging tax. I have added back the capital allowances and my NPV answer is 3.5m, but the examiner's answer is 1.9m. I think there is an error in the examiner's answer but i'm not sure. Can you help me sir