Solution:Let the numbers be x and y.According to the question,
2x + 3y = 36 ....... (i)
3x + 2y = 39 ....... (ii)
By equation (i) × 3 - (ii) × 2,
6x + 9y - 6x - 4y = 108 - 78
⇒ 5y = 30 ⇒ y = 30/5 = 6
From equation (i), we have,
2x + 3 × 6 = 36
⇒ 2x = 36 - 18 = 18
⇒ x = 18/2 = 9 and, y = 6
∴ The smaller number = 6