1. choose the biconditional that is equivalent to the definition, "a skyscraper is a very tall building." a. a building is a skyscraper if and only if it is very tall. b. if a building is a skyscraper, then it is very tall. c. if a building is very tall, then it is a skyscraper. d. a skyscraper is very tall if and only if it is a building.2. choose the biconditional statement with the same meaning as these two statements combined: statement 1: if a number is positive, then it is greater than zero. statement 2: if a number is greater than zero, then it is positive. a. a number is positive if and only if it is not zero. b. if a number is positive and greater than zero, then it is not negative. c. a number is positive if and only if it is greater than zero. d. if a number is non-negative, then it is positive.3. rewrite the statement, "a dog is a puppy if and only if it is young," as a conditional and its converse. a. conditional: a dog is a puppy. converse: a dog is young. b. conditional: a puppy is a dog. converse: a puppy is young. c. conditional: if a puppy is young, then it is a dog. converse: if a puppy is a dog, then it is young. d. conditional: if a dog is young, then it is a puppy. converse: if a dog is a puppy, then it is young.4. if p represents "x=7" and q represents "x2=49," which symbolic statement is true? a. p→q b. q→p c. p↔q d. all statements are true.5. which biconditional statement is true? a. a number is divisible by 9 if and only if it ends in 3. b. a quadrilateral is a square if and only if it has four right angles. c. the sum of two integers is positive if and only if the two integers are positive. d. a number is an even number if and only if it is divisible by 2.