A bag contains 77 coins consisting of quarters and nickels. The total value of the coins is $12.50. Write a system of equations that can be used to determine the number of quarters, x, and the number of nickels, y, in the bag. a
x + y = 77
0.25x + 0.5y = 12.5

b
0.25x +0.5 y = 77
x + y = 12.5

c
x + y = 77
0.25x + 0.05y = 12.5

d
0.25x + 0.05y =77
x + y = 12.5

Solve the system of equations using the substitution method. {y=−3x+7x=−2y−16 enter your answers in the boxes.

Sean is his dad build a tiled walkway in their backyard. the walkway will be 6060 feet long and 22 feet wide. the local hardware store sells tiles which are 22 by 22 feet and come in boxes of 66. how many boxes of tiles do they need?

Q.1 dr. frank needs to choose 3 students from her advanced biology course to attend a conference in hawaii. the course has 40 students. which of the following methods could dr. frank use to choose a simple, random sample of 3 students? select all that apply. 1 dr. frank could have the students line up from shortest to tallest, then use her birthdate, 2/5/39, to select 3 students from the line (the 2nd student, the 5th student, and the 39th student). 2. dr. frank could upload her class roster into a spreadsheet and use a ranom-number generating function to produce 3 random numbers. the students whose names are located in the rows with these 3 numbers on the spreadsheet would be chosen. 3. dr. frank could choose the students with the 3 highest grades in the class. 4. dr. frank could count to three, then the first students to come to the front of the classroom and grab a golden ticket from her hand would be selected. 5. dr. frank could ask all students to write their name on a card, place all of the cards in a hat, shake the hat, and then pull 3 cards out from the hat. the students whose names appear on those 3 cards will be selected. 6. dr. frank could ask for volunteers to go to the conference, then choose the first 3 students who raise their hands. q2. now, choose one of the methods that you did not select and explain why this method would not result in a simple, random sample: