A trader sold total 315 TV sets. He sold black and white TV sets at a loss of 6% and colour TV sets at a profit of 15%. Thus he gains 9% on the whole. The number of black and white TV sets, which he has sold, is :
The correct option is D 90 Using alligation, we get
Thus the ratio of B/W TV sets to the no. of colour TV sets = 2 : 5 Therefore, no. of B/W TV sets = 27×315=90.