A certain sum is invested at simple interest at 18% p.a. for two years instead of investing at 12% p.a. for the same time period. Therefore the interest received is more by Rs. 480. Find the sum?  Choose the most appropriate option: A) 7000 B) 7029 C) 4000 D) 2800 E) 2791
Let the sum be Rs. x.   (x * 18 * 2)/100 - (x * 12 * 2)/100 = 480 =&gt; 36x/100 - 24x/100 =480   =&gt; 12x/100 = 480 =&gt; x = 4000.Answer:4000
<result>C</result>
A certain sum is invested at simple interest at 18% p.a. for two years instead of investing at 12% p.a. for the same time period. Therefore the interest received is more by Rs. 480. Find the sum?