Q11. A neon sign flashes every 3 seconds, another sign flashes every 5 seconds, and a third flashes every 7 seconds. If they all flash together, how many seconds will pass before they all flash simultaneously again?Mathematics — LCM And HCF — Question 11 of 65A. 15 secondsB. 35 secondsC. 21 secondsD. 105 secondsPractice more Mathematics MCQs for entrance exam preparation on Examora.io.← Previous Question Next Question →