3 Write down the letter for the best answer to complete each statement, or for the correc answer to each question. 3.1 An algorithm refers to (a) a step-by-step solution to solve a specific problem (b) a collection of instructions that the computer can understand (c) a code that allows us to type in text materials (d) a set of math equations to derive the problem solution 3.2 The expression (1( (3-4%3) 3))) is (a) true (b) false (c) invalid (d) none of the above