How to calculate the theoretical TFLOPS of Nvidia T4's mixed-precision?

Nvidia T4 Mixed-Precision(FP16/FP32) is 65 TFLOPS. How to calculate 65 TFLOPS? https://www.nvidia.com/content/dam/en-zz/Solutions/Data-Center/tesla-t4/t4-tensor-core-datasheet-951643.pdf