The average age of 40 students in a class is 10years. If teacher's age is also included then average increases 1year then find the teacher's age?	Choose one
A) 59	B) 55	C) 61	D) 51	E) 36
Total age of 50 students = 40*10= 
<gadget id="calculator">40*10</gadget>
<output>400</output>
400   Total age of 51 persons= 41*11= 
<gadget id="calculator">41*11</gadget>
<output>451</output>
451   Age of teacher= 451-400= 
<gadget id="calculator">451-400</gadget>
<output>51</output>
51years   Answer is 51
<result>D</result>
The average age of 40 students in a class is 10years. If teacher's age is also included then average increases 1year then find the teacher's age?