Just 2 questions.....

A supermarket display consists of boxes of cereal. The bottom row has 23 boxes. Each row has three fewer boxes than the row below it. The display has six rows.

(A) Write and use a function to determine how many boxes are in the top row. Show your work.

(B) Use the appropriate formula to determine the number of boxes in the entire display. Show your work

oscar.a1551 Apr 19, 2019

#1**+2 **

First one

First term = 2(1) - 1 = 1

Last term =2(15) - 1 = 29

Sum = [ 1st term + last term ] * number of terms / 2 = [ 1 + 29] * 29/2 = 15 * 29 = 435

Second one

(A) Number in any row = 23 - 3(n - 1) = 26 - 3n

Number in row 6 = top row = 26 - 3(6) = 26 - 18 = 8

(B) Sum = [ number in 1st row + number in 6th row ] * [ number of rows] / 2 =

[ 23 + 8 ] * [ 6 ] / 2 = 31 * 3 = 93 = boxes in whole display

CPhill Apr 19, 2019