Correct Answer - Option 2 : RS 10
GIVEN:
Profit = 30%
No. of balls = 300
C.P = RS 900
Balls sold on C.P = 30%
EXPLANATION:
C.P of 1 ball = 900/300 = RS 3
30% of balls = 30/100 × 300 = 90
Remaining balls = 300 -90 = 210
C.P of 90 balls = 90 × 3 = RS 270
Required S.P = 130% of 900 = RS 1170
S.P of remaining 210 balls = 1170 - 270 = RS 900
S.P of 3 balls = 900/270 × 3 = RS 10
∴ He must sell 3 balls for RS 10