Suppose you have been offered two loan options: one at 4% simple interest for 5 years, and one at 5% simple interest for 4 years

Computation of Simple Interest:

Simple Interest = Principal*Rate*Time

For Option 1st:

Simple Interest = Principal*4%*5 

= Principal*0.20 or 0.20 P

For Option 2nd:

Simple Interest = Principal*5%*4 

= Principal*0.20 or 0.20 P

It will be depending upon the principal amount because the simple interest is calculated without undertaking interest on interest and it is directly calculating the effect of interest rate along with years.

If the interest and number of years are similar then the interest portion will be similar but if the principal amount is changing then the overall simple interest which will be charged will change, so it will be dependent upon the overall principal amount.