In a shop , there are three clocks with chime at intervals of 15 , 20 and 30 min respectively . They all chime together at 10 am . At what time will they all chime together againt ?

Options

A. 10 : 45 a.m
B. 10 : 50 a.m
C. 11 : 15 a.m
D. 11 a.m

Answer

D