Secondary 1 chevron_right Maths

I hope you can see it. I only need help with questions 7 and 8.

7) Raj takes his flu medicine every 6 hours and his cough medicine every 4 hours. If he takes both at 7.00 a.m, what is the next time that he has to take both his flu medicine and cough mixture again

8) Three bells toll at regular intervals of 15 minutes, 16 minutes and 36 minutes respectively. Given that they toll together at 2.00 p.m., at what time will they next toll together

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Those are the questions if you cannot see them