2/3 p-1, p+1,and 2/3 p+1 dre consecutive terms of an arithmetic progression find the value of p

Which of the following properties can be used to show

Twenty-five percent of the customers entering a grocery store between 5 p. m. and 7 p. m. use an express checkout. consider five randomly selected customers, and let x denote the number among the five who use the express checkout.

The perimeter of a triangle is 69 cm. the first is 5 cm shorter than the second side. the third side is twice as long the first side. find the length of each side