The GCF is based upon what integer divides evenly into two numbers; the LCM is based upon what integer two numbers share in a list of multiples. The GCF must be a prime number; the LCM must be a composite number.
the Kids that answered correct in any of questions 1 and 2 got at least one right so subtract the highest number which is 81 students by all the general amount of them, 145 that’s 64.