let x = amount for he bought + amount spent on repair
x--->[x+(20%of x)=1.2x]--->[1.2x-(10% of 1.2x)=1.08x]--->[1.08x+(10%of1.08x)]
Given in question 1.08x+(10% of 1.08x)=1188
from this x=1000 you get
Required answer = 1000 – 110 = 890.
Therefore answer is option D