instruction:
The task is to generate the correct answer for a given math problem.
question:
Problem: the ratio between the sale price and the cost price of an article is 12 : 7 . what is the ratio between the profit and the cost price of that article ?
answer:
5 : 7


question:
Problem: a shopkeeper loses 15 % , if an article is sold for rs . 102 . what should be the selling price of the article to gain 20 % ?
answer:
rs . 144


question:
Problem: a certain high school has 500 students . of these students , 50 are taking music , 20 are taking art , and 10 are taking both music and art . how many students are taking neither music nor art ?
answer:

440