Question
Total number of divisors of 480, that are of the form 4n + 2, n 0, is equal to :
- 2
- 3
- 4
- None of these
Hint:
In order to solve this question, we should know that the number of the divisor of any number where a, b, c are prime numbers and is given by (m + 1) (n + 1) (p + 1)….. By using this property we can find the solution of this question.
The correct answer is: 4
Detailed Solution
In this question, we have been asked to find the total number of divisors of 480 which are of the form 4n + 2,
o solve this question, we should know that the total number of divisors of any number x of the form where a, b, c … are prime numbers and is given by (m + 1) (n + 1) (p + 1)….. we know that 480 can be expressed as
So, according to the formula, the total number of divisors of 480 are (5 + 1) (1 + 1) (1 + 1) =
Now, we have been asked to find the number of divisors which are of the form 4n + 2 = 2 (2n + 1), which means odd divisors cannot be a part of the solution. So, the total number of odd divisors that are possible are (1 + 1) (1 + 1) according to the property.
Now, we can say the total number of even divisors are = all divisors – odd divisor
= 24 – 4
= 20
Now, we have been given that the divisor should be of 4n + 2, which means they should not be a multiple of 4 but multiple of 2. For that, we will subtract the multiple of 4 which are divisor of 480 from the even divisors.
And, we know that,
So, the number of divisors that are multiples of 4 are (3 + 1) (1 + 1) (1 + 1)
Hence, we can say that there are 16 divisors of 480 which are multiple of 4.
So, the total number of divisors which are even but not divisible by 2 can be given by 20 – 16 = 4.
Hence, we can say that there are 4 divisors of 480 that are of 4n + 2 form,
We can also solve this question by writing 4n + 2 = 2(2n + 1) where 2n + 1 is always an odd number. So, when all odd divisors will be multiplied by 2, we will get the divisors that we require. Hence, we can say a number of divisors of 4n + 2 form is the same as the number of odd divisors for 480.
Related Questions to study
If 9P5 + 5 9P4 = 10Pr , then r =
If 9P5 + 5 9P4 = 10Pr , then r =
The number of proper divisors of . . 15r is-
The number of proper divisors of . . 15r is-
If have a common factor then 'a' is equal to
If have a common factor then 'a' is equal to
A block C of mass is moving with velocity and collides elastically with block of mass and connected to another block of mass through spring constant .What is if is compression of spring when velocity of is same ?
A block C of mass is moving with velocity and collides elastically with block of mass and connected to another block of mass through spring constant .What is if is compression of spring when velocity of is same ?
If then ascending order of A, B, C.
If then ascending order of A, B, C.
The number of different seven digit numbers that can be written using only the three digits 1, 2 and 3 with the condition that the digit 2 occurs twice in each number is-
We know that there is not much difference between permutation and combination. Permutation is the way or method of arranging numbers from a given set of numbers such that the order of arrangement matters. Whereas combination is the way of selecting items from a given set of items where order of selection doesn’t matter. Both the word combination and permutation is the way of arrangement. Here, we will not use permutation because the order of toys is not necessary.
The number of different seven digit numbers that can be written using only the three digits 1, 2 and 3 with the condition that the digit 2 occurs twice in each number is-
We know that there is not much difference between permutation and combination. Permutation is the way or method of arranging numbers from a given set of numbers such that the order of arrangement matters. Whereas combination is the way of selecting items from a given set of items where order of selection doesn’t matter. Both the word combination and permutation is the way of arrangement. Here, we will not use permutation because the order of toys is not necessary.
The centre and radius of the circle are respectively
The centre and radius of the circle are respectively
The centre of the circle is
The centre of the circle is
The equation of the circle with centre at , which passes through the point is
The equation of the circle with centre at , which passes through the point is
The foot of the perpendicular from on the line is
The foot of the perpendicular from on the line is
The foot of the perpendicular from the pole on the line is
The foot of the perpendicular from the pole on the line is
The equation of the line parallel to and passing through is
The equation of the line parallel to and passing through is
The line passing through the points , (3,0) is
So here we used the concept of the equation of the line passing through two points. Here we also used the trigonometric terms to find the answer using the formulas. So the final solution is .
The line passing through the points , (3,0) is
So here we used the concept of the equation of the line passing through two points. Here we also used the trigonometric terms to find the answer using the formulas. So the final solution is .
Statement-I : If then A=
Statement-II : If then
Which of the above statements is true
Statement-I : If then A=
Statement-II : If then
Which of the above statements is true
If b > a , then the equation, (x - a) (x - b) - 1 = 0, has:
Here we used the concept of quadratic equations and solved the problem. We also understood the concept of discriminant and used it in the solution to find the intervals. Therefore, one of the roots will be in the interval of (−α,a) and the other root will be in the interval (b,α).
If b > a , then the equation, (x - a) (x - b) - 1 = 0, has:
Here we used the concept of quadratic equations and solved the problem. We also understood the concept of discriminant and used it in the solution to find the intervals. Therefore, one of the roots will be in the interval of (−α,a) and the other root will be in the interval (b,α).