Calculators were purchased at $70 per dozen and sold at $20 for three calculators. what is the profit on six dozen calculators?

Use set buikder notation to represent the following set: {, -2, -1, 0}

Offering 30 if a plus b plus c equals 68 and ab plus bc plus ca equals 1121, where a, b, and c are all prime numbers, find the value of abc. the answer is 1978 but i need an explanation on how to get that.

Twelve less than a number is at most 20