engineering recuitment NPCIL Plant Operator Mock Test Quantitative Aptitude Number System LCM and HCF
Six bells are ringing at intervals of 4, 6, 10, 15 and 20 minutes respectively. If they rang at 1:00 pm, together for the first time then how many times in all, would they ring till 11:00 pm (excluding 1:00 pm)?
1
11
2
10
3
6
4
5