# Archives

## 20 Dec 2021: The Hindu Analysis

UPSC Current Affairs Preparation: The Hindu Analysis Watch expert analysis of â€˜The Hinduâ€™ dated 20 Dec 2021. Important news and views to boost... View Article

## Economy This Week (11th Dec to 17th Dec 2021)

Economy is an important part of theÂ UPSC prelimsÂ and mains exams; this series titled â€˜Economy This Weekâ€™ has been initiated to address the need... View Article

## 19 Dec 2021: PIB Summary & Analysis

TABLE OF CONTENTS 1. Digital literacy and financial literacy also as important as basic literacy â€“ Vice President 2. PM felicitates freedom... View Article

## 20 Dec 2021: UPSC Exam Comprehensive News Analysis

CNA 20 Dec 2021:- Download PDF Here TABLE OF CONTENTS A. GS 1 Related B. GS 2 Related POLITY 1. Questioning the impartiality of the Election... View Article

(a) |A|n-1A (b) |A|nA (c) |A|n-2A (d) none of these Solution:  For any square matrix A, we know A-1 = adj A/|A| ..(i) Also AA-1 = I, where I... View Article

## derivative-of-mod-x-is

Solution: Let y = |x|  The modulus function |x| = x, when x ≥ 0 |x| = -x, when x<0 y = √x2 = (x2)1/2 dy/dx = ½ (x2)1/2 -1... View Article

## 2Ã—3 matrix

A 2×3 matrix is a matrix having 2 rows and 3 columns. We often say a two by 3 matrix or a matrix of dimension 2×3. A matrix is an... View Article

## 10 digit number

A 10 digit number has 10 digits and the first digit should not be zero. The first digit should be a number from 1 to 9. The smallest 10 digit... View Article

## Solve 10x = 30 for the value of x.

(a) 1/3 (b) 3 (c) 5 (d) None of these Solution: Given 10x = 30 Divide both sides of the equation by 10 => x = 30/10 => x = 3 Hence... View Article

## The sum first 25 natural numbers is

(a) 325 (b) 300 (c) 505 (d) None of these Solution: Sum of n natural numbers = n(n+1)/2 = 25×26/2 = 325 Hence option a is the answer.... View Article

## The binary number expression of the decimal number 31 is

(a) 1111 (b) 10111 (c) 11011 (d) 11111 Solution: In the binary system, we use 1 and 0 to represent numbers. To convert decimal number to... View Article

## The number which is subtracted from 27/13 to get -3/7 is

(a) 228/91 (b) 1/91 (c) 200/91 (d) 198/91 Solution: Let x be the required number. 27/13 - x = -3/7 => x = (27/13) + (3/7) LCM of 13... View Article

## Complete the series 98, 72, 14, __

Solution: Given series 98, 72, 14, __ Here the next number is obtained by multiplying 2 digits of the first number. 9 × 8 = 72 7... View Article

## What percent of 1 hour is 30 minutes?

Solution: 1 hour = 60 minutes Let x percentage of 60 minutes = 30 minutes => (x/100)60 = 30 => x = 3000/60 = 50 Hence 30 minutes is... View Article

## Simplify and reduce to a simple fraction: (4/5) Ã· (7/15) Ã— (8/9).

Solution: (4/5) ÷ (7/15) × (8/9) = (4/5) × (15/7) × (8/9) (multiply by reciprocal) =... View Article

## Find the number of subsets of the set 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 having 4 elements.

Solution: Number of elements = 11. We have to find the number of ways of choosing 4 elements of the set which has 11 elements. Number of ways... View Article

## Explain whether (3 Ã— 12 Ã— 101) + 4 is a prime number or a composite number.

Solution: Given number is (3 × 12 × 101) + 4 We have to check whether it is prime or composite. (3 × 12 × 101) + 4 =... View Article

## 3 chairs and 2 tables costs Rs. 700 and 5 chairs and 3 tables costs Rs. 1100. What is the cost of 2 chairs and 2 tables?

Solution: Let x be the cost of a chair and y be the cost of a table. 3x + 2y = 700 …(i) 5x + 3y = 1100 …(ii) Multiply (i) by 5... View Article

## Fill in the blanks with the most appropriate words. _______ earth moves round ______ sun.

(a) An/the (b) The/no article (c) The/the (d) no article/the Solution: ‘The’ is used as a definite article for a thing or person... View Article

## Find the cost price, if : S.P. = Rs.200 and loss = Rs.50.

Solution: Selling price = Rs.200 Loss = Rs.50 Cost price = selling price + loss = 200+50 = 250 Rs Hence the cost price is Rs. 250.... View Article