The plates of a parallel plate capacitor are separated by d. Two slabs of different dielectric constants \(\text{K}_1\, \text{and}\, \text{K}_2\) with thickness \(\displaystyle \frac{3}{8}\text{d}\) and \(\displaystyle \frac{d}{2}\), respectively are inserted in the capacitor. Due to this, the capacitance becomes two times larger than when there is nothing between plates.
If \(\text{K}_1\,=\,1.25\, \text{K}_2\), the value of \(\text{K}_1\) is: