There are 30 boys and 25 girls in a class. A student is chosen at random. Find the probability that the chosen student is a boy
Given that, Number of boys = 30 Number of girls = 25 Therefore, the total number of students 30 +... View Article
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If a + b + c = 3, then find the value of 1/(1 – a)(1 – b) + 1/(1 – b)(1 – c) + 1/(1 – c)(1 – a).
Given, a + b + c = 3 Now, [1/(1 – a)(1 – b)] + [1/(1 – b)(1 – c)]... View Article
Varun has 10 cards with numbers 1 to 10. In how many ways can a total of 15 be made using only three cards at a time?
A total of 15 should be made using only three cards at a time, which means no repetition is allowed.(1,... View Article
Write any 2 similarities and 2 differences of a right-angled isosceles triangle and obtuse-angled scalene triangle.
Two similarities between a right-angled triangle and an obtuse angled scalene triangle are:1. Both triangles contain two acute angles.2 The... View Article
How to find the HCF of 24 and 36?
Given numbers: 24, 36Prime factorization of 24 = 2 × 2 × 2 × 3 = 23 × 3Prime factorization... View Article
How do you find the GCD of two numbers?
GCD (Greatest Common Factor) of two or more numbers is the largest number that divides the given numbers. Suppose a... View Article
Write the formula for the perpendicular distance of a point from a line.
Consider a line L: Ax + By + C = 0 whose distance from the point P(x1, y1) is d.Thus,... View Article
The reduction of nitrobenzene in the presence of Zn/Ammonium chloride gives:
(A) Aniline (B) Azobenzene (C) Hydrazobenzene (D) N-phenyl hydroxylamine The Correct Answer is (D) N-phenyl hydroxylamine Solution: The reduction of... View Article
Which of the following statement is true about real gases?
(A) They show deviation from ideal behaviour (B) The molecules causes attractive forces on each other (C) They obey gas... View Article
Which of the following reagents can be used to distinguish between phenol and benzyl alcohol ?
(A) Bromine in CCl4 (B) Ferric chloride (C) Sodium hydroxide (D) Sodium bicarbonate The Correct Answer is (B) Ferric chloride.... View Article
Nitric acid does not react with:
(A) Zinc (B) Iron (C) Copper (D) Magnesium The Correct Answer is (D) Magnesium Solution: Nitric acid (HNO3) does not... View Article
Assertion: when a piece of copper metal is added to dilute sulphuric acid, the solution turns blue. Reason: Copper reacts with dilute sulphuric acid to form blue copper(II)sulphate solution.
(A) Both Assertion and Reason are false. (B) Assertion is true, but Reason is false. (C) Both Assertion and Reason... View Article
Make a classification key for the following groups of substances. a. rubber, paper, steel plate, glass.
Given groups of substances are: Glass Paper Rubber Seel plate Solution: Explore more such questions and answers at BYJU’S.
KMnO4 acts as an oxidising agent in an alkaline medium. When alkaline KMnO4 is treated with KI, iodide ion is oxidised to :
(A) I2 (B) IO (C) IO– (D) IO–3 The Correct Answer is (D) IO–3 Solution: When alkaline KMnO4 is treated... View Article
Which condition is not satisfied by an ideal solution?
(A)\(\begin{array}{l} \Delta _{mix} H = 0\end{array} \) (B)\(\begin{array}{l} \Delta _{mix} S = 0\end{array} \) (C)\(\begin{array}{l} \Delta _{mix} V = 0\end{array}... View Article
Which of the following statement is true about graphite?
(A) Graphite is an ionic solid (B) Graphite is a metallic solid (C) Graphite is a covalent solid (D) Graphite... View Article
Which of the following acid is the strongest acid?
(A) CH3COOH (B) HCOOH (C) (CH3)3CCOOH (D) (CH3)2CHCOOH The Correct Answer is (B) HCOOH Solution: Formic acid (HCOOH) is the... View Article
Gabriel phthalimide synthesis is used for the preparation of
(A) Primary amines (B) Secondary amines (C) Tertiary amines (D) Quaternary amines The Correct Answer is (A) Primary amines. Solution:... View Article
A gaseous compound of nitrogen and hydrogen contains 12.5 % hydrogen by mass. The molecular formula of the compound if its relative molecular mass is 32, is: [N=14, H=1]
(A) NH4 (B) N2H3 (C) N2H4 (D) N2H6 The Correct Answer is (C) N2H4 Solution: 100 g of the compound... View Article
The efficiency of a fuel cell is given by:
(A) \(\begin{array}{l}\frac{\Delta S}{\Delta G}\end{array} \) (B) \(\begin{array}{l}\frac{\Delta G}{\Delta H}\end{array} \) (C) \(\begin{array}{l}\frac{\Delta G}{\Delta S}\end{array} \) (D) \(\begin{array}{l}\frac{\Delta H}{\Delta G}\end{array} \)... View Article
