Question : After 55 years, a sum invested at simple interest at the rate of $r$ percent becomes twice of itself. What is the value of $r$?

Option 1: $\frac{17}{20}\%$

Option 2: $\frac{11}{30}\%$

Option 3: $\frac{13}{15}\%$

Option 4: $\frac{20}{11}\%$

Question : If a certain sum of money becomes double of itself in 3 years and 6 months at simple interest, then what will be the annual rate of interest?

Option 1: 22.5 percent

Option 2: 28.57 percent

Option 3: 30.53 percent

Option 4: 26.57 percent

Question : A sum was doubled with a 12.5% rate of simple interest per annum. Then time taken for that sum to be doubled is:

Option 1: $8\frac{1}{2}$ years

Option 2: 8 years

Option 3: 10 years

Option 4: $12\frac{1}{2}$ years

Question : If the period increases by 5 years, then simple interest increases by Rs. 3600 on a sum of Rs. 6000. What is the annual rate of interest?

Option 1: 15 percent

Option 2: 12 percent

Option 3: 12.5 percent

Option 4: 10 percent

Question : A, Rs 6,000 is invested at simple interest for 5 years and the annual rate of interest is 15 percent. B, Rs. 5,000 is invested at simple interest for 2 years and the annual rate of interest is 20 percent. What is the ratio of interests earned in A and B respectively?

Option 1: 19 : 12

Option 2: 9 : 4

Option 3: 16 : 5

Option 4: 18 : 11