A certain sum amount to $1400 in 2 yrs and $2000 in five years on certain fixed simple interest. In how many yrs would the amount be $2440 had it been put at the rate of interest compounded annually?	Choose the correct choice from the following choices.
A) 5 B) 4 C) 3 D) 2 E) 1
We can form equations as following:   Initial amount = P, Total amount after interest = T, Interest per year = I   T = P+I   Given T1 = P+2I = 1400T2 = P+ 5I = 2000   From this we get, P = 1000I = 200 $   Now we know that simple interest is&lt;Compound interest ( CI = SI only after 1st year if CI is compounded annually)   consider simple interest - after 1st yer it is 200$ , after 2nd years it is 400$ after 3rd yer it is 600$ , after 4th years it is 800$ after 5th years it is 1000$and after 6th year it is 1200$.   To get a 1040 $ compound interest the duration have to be &gt; 4 year and &lt; 6 years.   Only option fitting : Option 5.
<result>A</result>
A certain sum amount to $1400 in 2 yrs and $2000 in five years on certain fixed simple interest. In how many yrs would the amount be $2440 had it been put at the rate of interest compounded annually?