EASY
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Factors of 15. 

Important Questions on HCF-LCM

MEDIUM
The number of factors of 3600 is:
EASY
Calculate the total number of prime factors in the expression:

911×57×75×32×172

EASY
When 200 is divided by a positive integer x, the remainder is 8. How many values of x are there?
EASY
Let x be the smallest number, which when added to 2000 makes the resulting number divisible by 12,16,18 and 21. The sum of the digits of x is
EASY

The prime factorisation of 240 is:

(A) 23×32×5 

(B) 24×32×5

(C) 24×3×5

(D) 25×3×5

 

MEDIUM
Let S be the set of all ordered pairs (x, y) of positive integers satisfying the condition x2-y2=12345678. Then
MEDIUM
When 732 is divided by a positive integer x, the remainder is 12. How many values of x are there?
HARD
The number of 6-digit numbers of the form ababab (in base 10) each of which is a product of exactly 6 distinct primes is
MEDIUM
How many positive factors of 24 are there?
EASY
How many positive factors of 68 are there?
MEDIUM

Consider the following numbers:

1. 437

2. 797

3. 1073

How many of the above numbers are prime?

EASY

The total number of factors of 1156 is: 

(A) 9 

(B) 8 

(C) 10 

(D) 11 

MEDIUM

Consider the following statements in respect of all factors of 360:

1. The number of factors is 24.

2. The sum of all factors is 1170.

Which of the above statements is/are correct?

EASY
One of the factors of 82k+52k, where k is an odd number, is:
EASY
If a and b are positive integers such that a2-b2 is a prime number, then
MEDIUM
For an integer n, let Sn=n+1,n+2,., n+18. Which of the following is true for all n10 ?
HARD
Suppose a,b,c are positive integers such that 2a+4b+8c=328. Then a+2b+3cabc is equal to-
MEDIUM

Which of the following statement(s) is/are true?

I. There are 12 multiples of 9 from 7 to 109.

II. There are 9 multiples of 13 from 19 to 119.

EASY

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

MEDIUM

What is the number of Prime factor in 1518×410×69.