Average score of a group of athletes was 42 in certain event. When a new athlete join a group and scores equal to 250% of the average score of a group, then average of a group increases by 30%. How many athletes were there in a group before joining of a new athlete ?
Before joining new athlete, let there were 'x' athletes, so their total score = 42x
Score of a new athlete = (250/100)*42 = 105
New average = (42x + 105) / (x+1) = (130/100)*42
42x + 105 = (x+1)*54.6
12.6x = 50.4
x = 4
.'. There were 4 athletes before joining of a new athlete.
Correct Option 1)