What is the critical value? ( tc )

Two new drugs are being compared for effectiveness in lowering total cholesterol levels. On the sample of 15 subjects, drug A is found to lower total cholesterol by an average of 75 mg/dl with SS = 2025. On the sample of 10 subjects, drug B lowered the mean cholesterol level by 78 mg/dl with SS = 2005. Use a 0.01 level of significance to test the claim that the two drugs are equally effective assuming populations are normally distributed. ( Use equal variance t procedure called pooled variance t procedure )