Playing with Nu...

Which of the following numbers is divisible by 4?

Find first two common multiples of 12 and 16.

A school bus picking up children in a colony of flats stops at every eigth  building. Another school bus starting from the same place stops at every twelth building. Which is the first bus stop at which both of them will stop?

Write the largest 4-digit number and give its prime factorization.

Find the common factors of 18 and 24.

Which of the following numbers is a perfect number?

Two brands of biscuits are available in packs of 28 and 42 respectively. If I need to buy an equal number of biscuits of both kinds, what is the least number of packets of each kind I would need to buy?

Electricity poles occur at equal distances of 180 m along a road and heaps of stones are put at equal distances of 240 m along the same road. The first heap is at the foot of the first pole. How far from it along the road is the next heap which lies at the foot of a pole?

In the numbers 147*5  , replace * by the smallest number to make it divisible by 9. 

Which of the following pairs are always co-prime? 

(i) two prime numbers 

(ii) one prime and one composite number 

(iii) two composite numbers

A rectangular corridor is 20 m 16 cm long and 15 m 60 cm broad. It is to be paved with square tiles of the same size. Find the least possible number of such tiles.

An event was organized for charity.1763 people attended the event. Out of them 425 people donated Rs. 1000 each , 338 people donated 500 each and the rest donated an amount of Rs. 100 each. How much money was collected for charity?

What is the smallest number which when divided by 28, 42 and 56 gives a remainder of 3 each time?

The LCM and HCF of two numbers are 260 and 8 respectively. If one of the numbers is 40, find the other number.

Which of the following is a prime number?

Test the divisibility of 784645 the following numbers by 2: 

If x and y are two co-primes, then their LCM is

Determine prime factorization of 13915

7*4 is a three digit number with * as a missing digit. If the number is divisible by 6, the missing digit is.

Which of the following are co-primes?