Well, it seems like you've got the right idea in terms of using the conservation of energy equation (PE = KE) to solve this problem. However, there may be a couple of mistakes in your calculations.
First, when calculating the potential energy (PE) at the beginning of the problem, the height (h) for block A should indeed be h = 0.27cos(26°), since it is on an inclined plane. However, for block B, the height should be h = 0.27sin(26°), as it is hanging vertically.
Second, when calculating the final total kinetic energy (KE), you should sum up the kinetic energies of both block A and block B. Remember that the kinetic energy formula is KE = (1/2)mv^2, where m is the mass and v is the velocity. So, you need to calculate the final velocities of both blocks and use those to determine their kinetic energies.
To find the final velocity of block B, you can use the conservation of energy equation. Set the initial potential energy of block B (mass of B * g * h) equal to the final kinetic energy of both blocks. Solve for the final velocity of block B using v = sqrt(2gh).
Once you have the final velocities of both blocks, you can plug them into the kinetic energy formula to calculate their kinetic energies. Add those two kinetic energies together to find the total kinetic energy.
Keep in mind that some values, such as g (acceleration due to gravity) and the masses of block A and block B, will also need to be provided in order to solve the problem accurately.