A shopkeeper bought three watches `w_1, w_2` and `w_3` from a dealer and sold them to three different customers. The ratio of the selling prices of the watches `w_1, w_2 and w_3` was `2 : 3 : 4`. The shopkeeper gains `30% and 20%` on the watches `w_1 and w_2` respectively but loses 40% on the watch `w_3`. What was the shopkeeper's 'approximate percent gain or loss in the whole transaction? a. `16 %`profit b. `16 %` loss c. `15 %` loss d. Data inadequate