The average of 35 consecutive natural numbers is N. Dropping the first 10 numbers and including the next 10 numbers, the average is changed to M. If the value of M2 - N2 = 600, then the average of 3M and 5N is:
Answer & explanation
Correct answer: option 4
By adding 10 next consecutive number , Average increses by 10 .
So , N+10 = M
ATQ ,
M2 - N2 = 600
(N+10)2 - N2 = 600
20N = 500
N = 25 & M = 25 + 10 = 35
Sum of 3M & 5N = 3×35 + 5 ×25 = 1=5 + 125 = 230
Average = \(\frac{230}{2}\) = 115