Question : What is the ratio of the simple interest earned on a certain amount at the rate of 21% per annum for 8 years to that earned on the same sum at the same rate for 21 years?

Option 1: 8 : 21

Option 2: 21 : 5

Option 3: 5 : 21

Option 4: 21 : 8

Question : In a certain duration of time, a sum becomes 2 times itself at the rate of 5% per annum simple interest. What will be the rate of interest if the same sum becomes 5 times itself in the same duration?

Option 1: 20%

Option 2: 16%

Option 3: 10%

Option 4: 18%

Question : An amount becomes double in 8 years on simple interest. In how many years would Rs. 25,000 become Rs. 1,00,000 with the same rate of interest?

Option 1: 32

Option 2: 28

Option 3: 16

Option 4: 24

Question : A certain amount is lent at $x$% p.a. simple interest for 3 years. Instead, if the amount was lent at $3x$% p.a. simple interest for $y$ more years, the simple interest would have been seven times the earlier interest. What is the value of $y?$

Option 1: 3

Option 2: 4

Option 3: 5

Option 4: 6

Question : If Rs. 8,500 becomes Rs. 11,050 in 6 years at a certain rate of simple interest, and the rate then becomes 1.8 times higher, what will be the amount after 5 years on the same principal?

Option 1: Rs. 15,625

Option 2: Rs. 14,350

Option 3: Rs. 13,550

Option 4: Rs. 12,325