Question

How many whole numbers between 100 and 750 are multiples of both 18 and 24?

Q: Answer-How many whole numbers between 100 and 750 are multiples of both 18 and 24?

If a number is divisible by both 18 and 24, then it is divisible by L.C.M of 18 and 24 72 And, the required numbers will form an arithmetic progression So, First term a 72 X 2 144 Common difference d 72 Let required number of terms be n We have, a n - 1d 720 since 720 is the greatest multiple of 72 within the given range. Or, 144 72n - 1 720 Or, 144 72n - 72 720 Or, 72n 648 So, n 64872 9