instruction:
The task is to generate the correct answer for a given math problem.
question:
Problem: a house wife saved $ 5 in buying an item on sale . if she spent $ 48 for the item , approximately how much percent she saved in the transaction ?
answer:
10 %


question:
Problem: by selling an article for $ 195 , a person gains $ 45 . what is the gain % ?
answer:
30 %


question:
Problem: in the xy - coordinate system , if ( m , n ) and ( m + 2 , n + k ) are two points on the line perpendicular to x = 2 y + 5 , then k = ?
answer:

- 4