Show
Solution The correct option is A12.5%Explanation for the correct option:Consider that sum is invested under simple interest.The formula for the simple interest SI is given as SI=P×R×N100 (adsbygoogle = window.adsbygoogle || []).push({}); Where , P is the principal amount, R is the percentage rate of interest per annum,N is the number of years for which the sum is invested.The amountA is given as A=P+SIAccording to given condition it is known that the amount is doubled.⇒A=2P⇒2P=P+SI⇒SI=PSubstituting the values in the formula of simple interest we get (adsbygoogle = window.adsbygoogle || []).push({}); ⇒P=P×R×8100⇒R=1008⇒R=12.5%Thus the given amount will double in 8 years at 12.5%per annum.Hence, option(A) i.e. 12.5% is the correct answer.Solution The correct option is A 20 yearsLet the principal be P. As per the question, Amount = 2(Principal) = 2P SI = Amount - Principal = 2P - P = P By formula, R=SI×100P×T R=P×100P×10 =10 % So, the rate is 10% per annum. Now, the sum gets tripled. A = 3(Principal) = 3P SI = 3P - P = 2P T=SI×100P×R T=2P×100P×10 = 20 years (adsbygoogle = window.adsbygoogle || []).push({});Answer Verified
Hint: The formula for simple interest for a principal amount P, at the rate of R % for N years is given as \[SI = \dfrac{{PNR}}{{100}}\]. Use this to equate with the given information and find the required time.Complete step-by-step answer: Note: You might make a mistake by substituting the simple interest as equal to twice the principal amount. The amount, which is the sum of principal and simple interest is equal to twice the principal. Hence, the simple interest for the period will be equal to the principal amount. At what rate percent per annum will a sum of money double in 12.5 years?R ==1/12.5 ==0.08 x 100==8% simple interest to double your money in 12.5 years. N==~9 years to double your money at 8% compounded annually.
At what rate of simple interest will a sum of money double itself in?Hence, R = 5%. Q.
At what rate per cent by simple interest will a sum of money double itself in 5 years 4 months?Let P be the principal amount and R be the rate of interest. ∴ The rate of simple interest p.a. is 20%.
At what rate per cent per annum simple interest will a sum doubles itself in 10 years?Hence the required rate in which the sum becomes double itself in 10 years is 10%.
|