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. 840. Find the sum?  Pick one:
A) 7000  B) 7029  C) 2778  D) 2800  E) 2791
Let the sum be Rs. x.   (x * 18 * 2)/100 - (x * 12 * 2)/100 = 840 =&gt; 36x/100 - 24x/100 =840   =&gt; 12x/100 = 840 =&gt; x = 7000.7000nswer:7000
<result>A</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. 840. Find the sum?