Monthly earnings of Christopher is Rs. 28000
Monthly earnings of jane is Rs.36000
Total earnings
=Rs.(28000+36000)=Rs.64000
Therefore the required ratios are,
To find Ratio of Christopher earnings to their total earning we have,
= Christopher monthly earnings / Their total monthly earnings
= Rs.36000 / Rs.64000
= 9 / 16
Hence, the Ratio of Monthly earnings of Christopher to their total earning is 9:16