Number of days required by A to finish the work : 15 days

Work done by A in one day: \(\frac{1}{15}\)

B can work 50% more efficiently than A,

∴ B's one day work = 150% of = \(\frac{150}{100}\times\frac{1}{15}=\frac{1}{10}\)

∴ B alone can complete the work in 10 days.