1.
For some integer M, every odd integer is of the form
Correct Answer
D. 2q+1
Explanation
The given answer, 2q+1, is the correct form for every odd integer. In the given options, q represents an integer, and 2q represents an even integer. Adding 1 to an even integer will always result in an odd integer. Therefore, the expression 2q+1 represents every odd integer.
2.
If the HCF of 65 and 117 is expressible in the form 65m - 117(65m minus 117) then the value of m is?
Correct Answer
B. 2
Explanation
The given question asks for the value of m if the highest common factor (HCF) of 65 and 117 can be expressed in the form 65m - 117(65m minus 117). To find the value of m, we need to simplify the expression and equate it to the HCF. By simplifying the expression, we get 65m - 117(65m - 117) = 65m - 117(65m) + 117(117). This simplifies further to 65m - 7605m + 13689. The HCF of 65 and 117 is 13. By equating the expression to 13, we get 65m - 7605m + 13689 = 13. Solving this equation gives us m = 2. Therefore, the correct answer is 2.
3.
N square minus 1 is divisible by 8, if N is
Correct Answer
A. An integer
Explanation
The given expression N^2 - 1 can be factored as (N+1)(N-1). Since we are looking for values of N that make the expression divisible by 8, we need to consider the factors of 8. The factors of 8 are 1, 2, 4, and 8. Since (N+1)(N-1) is the product of two consecutive integers, one of them must be even. Therefore, N can be any integer, whether it is natural, odd, or even, as long as it is an integer.
4.
The number of polynomials having zeroes -2 and 5 is?
Correct Answer
D. More than 3
Explanation
The number of polynomials having zeroes -2 and 5 is more than 3 because there are infinite polynomials that can be formed with these two zeroes. A polynomial can have multiple terms and coefficients, allowing for an infinite number of combinations and possibilities. Therefore, the number of polynomials that can have -2 and 5 as zeroes is more than 3.
5.
A right circular cylinder of radius r and height h (h=2r) just encloses a sphere of diameter
Correct Answer
C. 2r
Explanation
The correct answer is 2r. A right circular cylinder with a height equal to twice its radius will have a diameter equal to twice its radius as well. Since the sphere is enclosed within the cylinder, the diameter of the sphere must be equal to the diameter of the cylinder, which is 2r.
6.
If 2x-3y=7 and (a+b)x-(a+b-3)y=4a+b represent coincident lines, then a and b satisfy the equation.
Correct Answer
C. A-5b=0
Explanation
The given equations represent two lines. If the lines are coincident, it means they are the same line. In order for two lines to be the same, the ratios of their coefficients should be equal. Comparing the coefficients of x and y in the two equations, we can see that (a+b)x-(a+b-3)y=4a+b has the same ratio as 2x-3y=7. Therefore, a and b satisfy the equation a-5b=0.
7.
The sum of first 20 odd natural number is
Correct Answer
C. 400
Explanation
The sum of the first 20 odd natural numbers can be calculated by using the formula for the sum of an arithmetic series. The formula is given by n^2, where n is the number of terms in the series. In this case, n is 20. Therefore, the sum of the first 20 odd natural numbers is 20^2 = 400.
8.
If A(2,2), B(-4,-4) and C(5,-8) are the vertices of a triangle, then the length of the median through vertex C is
Correct Answer
C. √85
Explanation
To find the length of the median through vertex C, we first need to find the midpoint of the side opposite to C. The midpoint of AB can be found by taking the average of the x-coordinates and the average of the y-coordinates of A and B. The midpoint is (-1, -1).
Next, we calculate the distance between the midpoint (-1, -1) and vertex C(5, -8) using the distance formula.
Distance = √[(5 - (-1))^2 + (-8 - (-1))^2]
= √[(6)^2 + (-7)^2]
= √[36 + 49]
= √85
Therefore, the length of the median through vertex C is √85.
9.
All circles are .......
Correct Answer
Similar
Explanation
The word "similar" is the correct answer because the question states "All circles are..." which implies that all circles possess a common characteristic or property. The word "similar" accurately describes this common characteristic as it means having a resemblance or likeness in qualities or characteristics. Therefore, all circles share similar properties, such as having a curved shape and all points on the circumference being equidistant from the center.
10.
If radii of two concentric circles are 4cm and 5cm, then the lengths of each chord of one circle which is tangent to the circle is.
Correct Answer
B. 6 cm
Explanation
The length of each chord of one circle which is tangent to the circle can be found by using the theorem that states that the length of a chord that is tangent to a circle is equal to the square root of the product of the lengths of the segments it divides the tangent line into. In this case, the lengths of the segments are 4 cm and 5 cm, so the length of the chord is the square root of (4 cm * 5 cm) which is equal to 6 cm.