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

Problem: a and b have monthly incomes in the ratio 5 : 6 and monthly expenditures in the ratio 3 : 4 . if they save rs . 1800 and rs . 1600 respectively , find the monthly income of b 
Options: a ) rs . 3400 , b ) rs . 2700 , c ) rs . 1720 , d ) rs . 7200 , e ) rs . 8200
d

Problem: if all 6 are replaced by 9 , the algebric sum of all numbers from 1 to 100 ( both inclusive ) varies by , 
Options: a ) 980 , b ) 330 , c ) 660 , d ) 990 , e ) 300
b

Problem: the l . c . m . of two numbers is 42 . the numbers are in the ratio 2 : 3 . then sum of the number is : 
Options: a ) 28 , b ) 32 , c ) 35 , d ) 53 , e ) 54

c