The temperature of a body increases from 310 K to 340 K. The...

Initial temperature, $T_1 = 310$ K

Final temperature, $T_2 = 340$ K

Change in temperature, $\Delta T = T_2 - T_1 = 340 - 310 = 30$ K

Since the size of one degree on the Celsius scale is equal to the size of one unit on the Kelvin scale, the change in temperature in degree Celsius is equal to the change in temperature in Kelvin.

$\Delta T = 30^{{}^{\circ}}\text{C}$

Answer: 30°C