In this task, you need to answer the given multiple-choice question on the general math. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

Problem: find the principle on a certain sum of money at 5 % per annum for 3 1 / 5 years if the amount being rs . 580 ? 
Options: a ) rs . 500 , b ) rs . 5100 , c ) rs . 530 , d ) rs . 540 , e ) none of these
a

Problem: 5.005 / 4.004 = 
Options: a ) 1.05 , b ) 1.50015 , c ) 1.501 , d ) 1.5015 , e ) 1.25
e

Problem: a bakery has 6 employees . it pays annual salaries of $ 18,000 to each of 2 employees , $ 20,000 to 1 employee , and $ 21,000 to each of the remaining 3 employees . which number is closest to the average ( arithmetic mean ) annual salary of these employees ? 
Options: a ) $ 19,200 , b ) $ 19,500 , c ) $ 19,800 , d ) $ 20,000 , e ) $ 20,400

c