Given, point (2,3) lies on the line. So, the point (2, 3) is the solution of 3x - (a -1) y = 2a - 1 On putting x = 2 and y = 3 in given solution. ∴ 3 × 2 - (a-1) × 3 = 2a - 1 ⇒ 6 - 3a + 3 = 2a - 1 ⇒ - 3a - 2a = - 1 - 3 - 6 ⇒ -5a = -10 ⇒ a = 2 Also, (2, 3) is the solution of 5x + (1- 2a) y = 3b. on putting x = 2 and y = 3 in given equation ∴ 5 × 2 + (1 - 2a) × 3 = 3b --- i) Now, putting the value of a = 2 in eq. (i) we get 5 × 2 + (1 - 2 × 2) × 3 = 3b ⇒ 10 - 9 = 3b ⇒ 1 = 3b ⇒ 1 / 3 = b Hence, the value of b is 1 / 3.