WHAT IS THE ANSWER TO THIS PROBLEM

Question

LISA IS STRINGING BEADS TO MAKE A NECKLACE, AN ANKLET, AND A BRACELET.THE NECKLACE USES 50% OF THE STRING. THE ANKLET IS 60% SHORTER THAN THE NECKLACE.THE BRACELET NEEDS 25% LESS STRING THAN THE ANKLET. HOW LONG IS THE ORIGINAL, UNCUT STRING IF THE BRACELET MEASURES 18 CM

Answer 1

Let s = length of original string

 

necklace = 0.5s

 

The anklet is 60% shorter than the necklace so it uses

40% of 0.5s = (.4)(.5s) = 0.2s

 

The bracelet needs 25% less string than the anklet so it

uses 75% as much string as the anklet:

75% of 0.2s = 0.75(0.2s) = 0.15s

 

The bracelet is 18cm so:

0.15s = 18

s = 18/0.15 = 120 cm