Piyali bought 28.5 metres of cloth. She used 2.5 metres of the cloth to make a shirt and 3/5 of cloth that used for the shirt, to make a matching pair of shorts. She sewed 6 shirts and some pairs of shorts for her children. If she had 1.5 metres of cloth left, then how many pairs of shorts did she sew ?
A7
B8
C9
D10