Question

if simple interest on a certain sum of money for x years at x% per annum is Rs.x, then the sum is​

Answer 1

simple interest = x
time=x yrs
rate of interest =x
principal = x×100/x×x
100/x is the sum

Answer 2

$(x \times x \times x) \div 100 = x$
now,
${x}^{3} = 100x$
${x}^{3} \div x = 100 \\ {x}^{2} = 100 \\ x = \sqrt{100 } \\ x = 10$
hence sum is rs.10