Find the HCF of the numbers 40 and 56 by division method.

A book seller has 175 English books, 245 Science books and 385 Mathematics books. He wants to sell the books in a box, subject-wise in equal numbers. What will be the greatest number of the boxes required? Also find the number of books for each subject in a box.

Find the smallest number that can be divided by 254 and 508 which leaves the remainder 4.

Find A as required:
(i) The greatest 2 digit number 9A is divisible by 2.
(ii) The least number 567A is divisible by 3.
(iii) The greatest 3 digit number 9A6 is divisible by 6.
(iv) The number A08 is divisible by 4 and 9.
(v) The number 225A85 is divisible by 11.

The product of 2 two digit numbers is 300 and their HCF is 5. What are the numbers?

Wilson, Mathan and Guna can complete one round of a circular track in 10, 15 and 20 minutes respectively. If they start together at 7 a.m from the starting point, at what time will they meet together again at the starting point?

The sum of any two successive odd numbers is always divisible by 4. Justify this statement with an example

Find the HCF of the numbers 18, 24 and 30 by factor tree method.

Find the LCM of 156 and 124.

There are four Mobile Phones in a house. At 5 a.m, all the four Mobile Phones will ring together. Thereafter, the first one rings every 15 minutes, the second one rings every 20 minutes, the third one rings every 25 minutes and the fourth one rings every 30 minutes. At what time, will the four Mobile Phones ring together again?