Converting given measurements into centimeters 4m 96 cm = 400+96 = 496 cm 4m 3cm = 400+3 =403 cmTo find the side of the largest possible brick , the side of brick must divide length as well as breadth exactly. Using division method 403)496(1 403 93) 403 (4 370 31) 93 (3 93 0HCF = 31 Side of the largest possible square brick =31cm
Interval of change = (L.C.M of 48,72,108)sec.=432sec. So, the lights will agin change simultaneously after every 432 seconds i.e,7 min.12sec Hence , next simultaneous change will take place at 8:27:12 hrs.