We use cookies to personalise content and advertisements and to analyse access to our website. Furthermore, our partners for online advertising receive pseudonymised information about your use of our website. cookie policy and privacy policy.
 
+0  
 
0
64
1
avatar+240 

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

 Apr 19, 2019
 #1
avatar+100483 
+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

 

 

cool cool cool

 Apr 19, 2019

28 Online Users

avatar