Let the amount invested in Scheme A be x, then the amount invested in Scheme B will be (13900 - x).

Using the formula for simple interest, we can calculate the interest earned in Scheme A as:

Interest A = (x * 14 * 2) / 100 = 0.28x

Similarly, the interest earned in Scheme B can be calculated as:

Interest B = ((13900 - x) * 11 * 2) / 100 = 0.22(13900 - x)

Given that the total interest earned is Rs. 3508, we can write the equation:

Interest A + Interest B = 3508

0.28x + 0.22(13900 - x) = 3508

0.28x + 3058 - 0.22x = 3508

0.06x = 450

x = 7500

Therefore, the amount invested in Scheme B is:

13900 - x = 13900 - 7500 = Rs. 6400

Hence, Mr. Thomas invested Rs. 6400 in Scheme B.