Question

The average of 10 consecutive odd numbers is 120. What is the average of the 5 largest numbers?

Answer 1

(111+113+115+117+119+121+123+125+127+129)/10=120

Average of the largest five numbers:-
(129+127+125+123+121)/5=125

Thus, the answer is 125.

Answer 2

Let the nos be x , x+2 , x+ 4 ...... X+ 18than according to question ( x+ x+ 2 +x+4......x+18)/10 = 120 => 10x +90 = 1200 => 10x = 1200- 90=> x= 110/10 => x= 11 than largest 5 nos will be x+ 18 = 11+ 18 = 29 , 27 , 25 , 23 ,21 now their average = 21+23+25+27+29/5 = 125/5 = 25