Find the L.C.M of $$ {6x}{y^{2}z},{8x^{2}{y^{3}z^{2},{12{x^{3}{y^{3}z^{3}}}}}}$$.

The LCM of two positive integers is twice the larger number and the HCF of the two numbers is 3. The smaller number is:

Find the LCM of the fractions $${2\over 5}$$, $${3\over 7}$$ and $${4\over 9}$$

Two pipes of length 36 metre and 40 metre are to be cut into equal pieces without leaving any extra length of pipe. Find the number of such pieces if pipes are to be cut of maximum length.

The LCM of three different numbers is 120. Which of the following cannot be their HCF? 

What is the Highest Factor of $$ {2^{3}×{3^{5}}} and \ {2^{3}×{3^{5}}}$$ ?

The least number which when divided by 4, 6, 8 and 9 leave zero remainders in each case and when divided by 13 leaves a remainder of 7 is: 

Three Alarm make a beep after every 48 sec, 72 sec and 108 sec respectively. They beeped together at 10 a.m. The time when they will next make a beep together at the earliest is