Compute the specified quantity The simple Interest on a 100

Compute the specified quantity. The simple Interest on a $ 1,000 loan at 10% per year amounted to $ 900 At what time t did the loan mature? t = yr.

given,

P=$1000

r = 10 %

now , required amount ,A = $900

we have the formula simple interest,

A=Ptr/100 (r should be in %)

900 = 1000*t*10/100

900= 100*t

t = 9 years

therefore, after 9 years, loan matures