In this task, you need to provide the correct option for a given problem from the provided options.
--------
Question: Problem: find the ratio in which rice at rs . 7.20 a kg be mixed with rice at rs . 5.70 a kg to produce a mixture worth rs . 6.30 a kg ?
Options: a ) 1 : 3 , b ) 2 : 3 , c ) 3 : 4 , d ) 4 : 5 , e ) none of these

Answer: b

Question: Problem: find the number of zeroes at the end of 50 !
Options: a ) 10 , b ) 11 , c ) 12 , d ) 13 , e ) 14

Answer: c

Question: Problem: there are 200 doctors and nurses at a hospital . if the ratio of doctors to nurses is 4 to 6 , how many nurses are at the hospital ?
Options: a ) 110 , b ) 120 , c ) 130 , d ) 140 , e ) 150

Answer:
b