currency mangement

referring to q 8 part c 2011 please i need your help

im trying to calculate the return by using the standard formula but there is some discrepency if u can please assist me to sort that out i will b very pleased

r dc = 25/35[27.5/25*.87/.8]+10/35[8/10*.87/.8]-1


cant figure out how 400k is coming out of it

please help me