Is the 4% and 5% interest anually ?
Or monthly/daily/hourly and so forth ?
annually i think. it doeesnt specify
Alright. The idea here is pretty simple. Consider this:suppose the first sum was X and the second sum was Y. |dw:1437351988132:dw|
The total sum deposited being 1500$ simply means that X+Y=1500.
The interest earned for each sum is simply: |dw:1437352107232:dw|
Mathematically we can write that as: 4X/100 + 5Y/100 = 67 (which is the total interest earned that year)
And now we simply have to solve two equations with two unknown variables. X+Y=1500 4X/100 + 5Y/100 = 67 We multiply the second equation with 100: X+Y=1500 4X+5Y=6700 We multiply the first equation with 5: 5X+5Y=7500 4X+5Y=6700 We subtract the second equation from the first equation: X=800 Which is the answe you are looking for.
thank you for the help!!!