The simple interest on a sum of money at 5% per annum for 4 years and 3 years differs by Rs. 42.
The difference between 4 years and 3 years is 1 year. Therefore, Rs. 42 represents the simple interest for 1 year.
Given:
Rate (R)=5% per annum
Time (T)=1 year
Simple Interest (SI)=Rs.42
Using the simple interest formula:
SI=100P×R×T
Substituting the values:
42=100P×5×1
42=1005P
42×100=5P
4200=5P
P=54200
P=840
Therefore, the sum is Rs. 840.