The mean salary in ICM ltd. was Rs 1500, and the standard deviation was Rs 400. A year later each employee got a Rs 100 raise. After another year each employee's salary was increased by 20%. The standard deviation of the current salary is?	Choose the correct choice from the following choices
A) Rs 400
B) Rs 480
C) Rs 600
D) Rs 700
E) Rs 800
Mean salary was Rs 1500   Standard deviation = Rs 400   After 1 year all the employees got a uniform rise of Rs 100.   So, there will be no change in standard deviation.   After another year, every employee's salary was increased by 20%.   So, standard deviation will be increased by 20%.   Standard deviation=400×   120   100   = Rs 480   Answer Rs 480
<result>B</result>
The mean salary in ICM ltd. was Rs 1500, and the standard deviation was Rs 400. A year later each employee got a Rs 100 raise. After another year each employee's salary was increased by 20%. The standard deviation of the current salary is?