In this task, you need to provide the correct option for a given problem from the provided options.

Problem: income and expenditure of a person are in the ratio 5 : 4 . if the income of the person is rs . 17000 , then find his savings ? 
Options: a ) 3600 , b ) 3400 , c ) 3608 , d ) 3602 , e ) 3603
b

Problem: a certain telephone company offers two plans , a and b . under plan a , the company charges a total of $ 0.60 for the first 4 minutes of each call and $ 0.06 per minute thereafter . under plan b , the company charges $ 0.08 per minute of each call . what is the duration of a call , in minutes , for which the company charges the same amount under plan a and under plan b ? 
Options: a ) 2 , b ) 9 , c ) 15 , d ) 18 , e ) 30
d

Problem: on a certain farm the ratio of horses to cows is 6 : 1 . if the farm were to sell 15 horses and buy 15 cows , the ratio of horses to cows would then be 3 : 1 . after the transaction , how many more horses than cows would the farm own ? 
Options: a ) 40 , b ) 50 , c ) 60 , d ) 70 , e ) 80

d