Find the rate of Simple interest by which a given money is doubled in 15 years

At what rate of simple interest a certain sum will be doubled in 15 years?

At what rate of simple interest a certain sum will be doubled in 12 years ?

At what rate of simple interest a certain sum will be doubled in 14 years

At what rate percent by simple interest, will a sum of money double itself in 5 years 4 months ?

Consider the following statements If a sum of money is lent at simple interest, then the money gets doubled in 5 years if the rate of interest is 16 2/3% money gets doubled in 5 years if the rate of interest is 20% money becomes four times in 10 years if it gets doubled in 5 years. Of these statements, (a) 1 and 3 are correct (b) 2 alone is correct (c) 3 alone is correct (d) 2 and 3 are correct

The rate of simple interest per annum at which a sum of money double itself in 16frac(2)(3) yr is

2400 becomes 2976 in 3 years at a certain rate of simple interest. What sum of money will become 5016 in 4 years at the same rate of interest?