Home › UP Board Class 10 › mathematics › Real Numbers › Two bells ring at intervals of 9 and 15 minutes.…
Two bells ring at intervals of 9 and 15 minutes. They ring together at noon. When do they ring together again?
Aafter 9 min
Bafter 15 min
Cafter 30 min
Dafter 45 min
Answer & Solution
Correct answer: D. after 45 min
Meeting time = LCM(9, 15). 9 = 3², 15 = 3·5. LCM = 3²·5 = 45. They ring together again 45 min after noon.
Related questions
If p is prime and p divides a², then p divides a. This step is used to prove which number Numbers that fill the number line completely (every point on the line corresponds to such Which of the following will have a terminating decimal expansion?The decimal expansion of 1/6 is:Will the decimal expansion of 13/125 terminate?Which of the following is an irrational number?If HCF(a, b) = 9 and a · b = 1620, find LCM(a, b).Find the LCM of 12 and 18.