If the annual rate of simple interest increases from 10% to 12 1/2 %, a man's yearly income increases by Rs. 1250. His principal in Rs. is?
Choose the correct choice from the following.
A) 29879	B) 50000	C) 72900	D) 27992	E) 89282
Let the sum be Rs. x. Then,   (x * 25/2 * 1/100) - (x * 10 * 1)/100 = 1250   25x - 20x = 250000   x = 50000   Answer: 50000
<result>B</result>
If the annual rate of simple interest increases from 10% to 12 1/2 %, a man's yearly income increases by Rs. 1250. His principal in Rs. is?