Gain or loss. By selling 288 pens, the shopkeeper lost the S. P. of 12
pens. Find his loss
per
cent.

let sp of 1 pen is x rs

sp of 12 pens is 12x rs

so loss by selling 288 pens = 12x rs

now selling price of 288 pens 288x rs

so 12x= cp-sp

or 12x=cp-288x

or cp=300x

now loss percent = (12x/300x)*100=4%

4

step-by-step explanation:

is the anwser b. (-13)?