# Lecture-3

Substitution Method 00:01:53 NCERT Exercise 3.3 Question 1

00:21:33 NCERT Exercise 3.3 Question 2 Solve 2x + 3y = 11 and 2x – 4y = – 24 and hence find the value of ‘m’ for which y = mx + 3.

00:25:03 NCERT Exercise 3.3 Question 3 part (i) The difference between two numbers is 26 and one number is three times the other. Find them.

00:28:03 NCERT Exercise 3.3 Question 3 part (ii) The larger of two supplementary angles exceeds the smaller by 18 degrees. Find them.

00:31:33 NCERT Exercise 3.3 Question 3 part (iii) The coach of a cricket team buys 7 bats and 6 balls for ₹ 3800. Later, she buys 3 bats and 5 balls for ₹ 1750. Find the cost of each bat and each ball.

00:37:03 NCERT Exercise 3.3 Question 3 part (iv) The taxi charges in a city consist of a fixed charge together with the charge for the distance covered. For a distance of 10 km, the charge paid is ₹105 and for a journey of 15 km, the charge paid is ₹155. What are the fixed charges and the charge per km? How much does a person have to pay for travelling a distance of 25 km?

00:42:23 NCERT Exercise 3.3 Question 3 part (v) A fraction becomes 9/11, if 2 is added to both the numerator and the denominator. If, 3 is added to both the numerator and the denominator it becomes 5/6. Find the fraction.

00:48:03 NCERT Exercise 3.3 Question 3 part (vi) Five years hence, the age of Jacob will be three times that of his son. Five years ago, Jacob’s age was seven times that of his son. What are their present ages?