Correct Answer - Option 1 : 320
Given:
Four racers A, B, C and D runs certain distances. The distance D runs is double than that of A. The average distance A and C runs is 230 metres. B runs 100 metres more than A. The average distance all four of them run is 245 metres.
Formula:
Average of n numbers a1, a2 ... an = (a1 + a2 + ... an)/n
Calculation:
Let A travel a distance of x metres
D travels = 2x metres
B = x + 100
Given,
(A + C)/2 = 230
A + C = 460
A is x,
C = 460 -x
As per question,
x + x +100 + 460 – x + 2x = 980
3x + 560 = 980
3x = 420
x = 140
C = 460 – x = 460 – 140 = 320