23. Three bells ring at intervals o...
Question
Fullscreen

23. Three bells ring at intervals of 15, 20 and 30 minutes respectively. If they all ring at 11.00 a.m. together, at what time will they next ring together? RRB NTPC (Phase 1) 2016 (1) 11.30 a.m. (2) 12 noon (3) 12.30 p.m. (4) 1.00 p.m.

11th - 12th Class
Maths
Solution
66
Rating
3.0 (1 ratings)
Fullscreen
23. (2) LCM of 15,20 and 30 min, [ begin{array}{c|l} 2 & 15,20,30 hline 2 & 15,10,15 hline 3 & 15,5,15 hline 5 & 5,5,5 hline 1, & 1,1 = & 2 times 2 times 3 times 5 = & 60 mathrm{min} end{array} ] ( therefore quad ) Required time ( =11: 00+1 mathrm{h} ) ( =12 ) noon
Quick and Stepwise Solutions Just click and Send Download App OVER 20 LAKH QUESTIONS ANSWERED Download App for Free