Help me with math question

You have two cards with a sum of -12 in both hands. a. what two cards could you have? b. you add two more cards to your hand, but the total sum if the cards remains the same, (-12).

This week, conrad will work 1 3/4 times longer than last week. giovanni will work 1 1/3 times longer than last week. sally will work 2/3 the number of hours she worked last week. match each employee's name to the number of hours he or she will work this week

1. there are 25 students who started computer programming in elementary school and 25 students who started computer programming in middle school. the first group had a mean final project grade of 95% and the second group had a mean final project grade of 92%. the line plot shows the differences after 10 rerandomizations. determine whether the difference in the means of the two groups is significant based on the line plot. explain your answer.