What is a three digit number divisible by 3 and 4 and how

Keith bought a soft drink for 4 dollars and 9 candy bars .he spent a total of 31 dollars .how much did each candy bar cost?

Solve 2x+y=3 x+y=5 in substitution method

In a survey of 1015 adults, a polling agency asked, "when you retire, do you think you will have enough money to live comfortably or not. of the 1015 surveyed, 534 stated that they were worried about having enough money to live comfortably in retirement. construct a 90% confidence interval for the proportion of adults who are worried about having enough money to live comfortably in retirement.