Lecture-4


Elimination Method 00:01:11 NCERT Exercise 3.4 Question 1

00:16:11 NCERT Exercise 3.4 Question 2 part (i) If we add 1 to the numerator and subtract 1 from the denominator, a fraction reduces to 1. It becomes ½ if we only add 1 to the denominator. What is the fraction?

00:20:11 NCERT Exercise 3.4 Question 2 part (ii) Five years ago, Nuri was thrice as old as Sonu. Ten years later, Nuri will be twice as old as Sonu. How old are Nuri and Sonu?

00:25:02 NCERT Exercise 3.4 Question 2 part (iv) Meena went to a bank to withdraw ₹ 2000. She asked the cashier to give her ₹ 50 and ₹ 100 notes only. Meena got 25 notes in all. Find how many notes of ₹ 50 and ₹ 100 she received.

00:30:01 NCERT Exercise 3.4 Question 2 part (v) A lending library has a fixed charge for the first three days and an additional charge for each day thereafter. Saritha paid ₹ 27 for a book kept for seven days, while Susy paid ₹ 21 for the book she kept for five days. Find the fixed charge and the charge for each extra day.

00:34:51 NCERT Exercise 3.4 Question 2 part (iii) The sum of the digits of a two-digit number is 9. Also, nine times this number is twice the number obtained by reversing the order of the digits. Find the number.