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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.

65% of students in your school participate in at least one after school activity. if there are 980 students in you school, how many do not participate in an after school activity?

When 142 is added to a number the result is 64 more then 3 times the number. option 35 37 39 41