Find the HCF of $13$ and $39$.

The total number of factors of 1156 is: 

(A) 9 

(B) 8 

(C) 10 

(D) 11 

What is the number of Prime factor in ${15}^{18}$$\times$$4^{10}$$\times$$6^9$.

The prime factorisation of 240 is:

(A) $2^3\times$$3^2\times 5$ 

(B) $2^4\times 3^2\times 5$

(C) $2^4\times 3\times 5$

(D) $2^5\times 3\times 5$

The sum of all the factors of $156$ is: 
(A) $392$
(B) $235$
(C) $390$
(D) $379$