Answer:a
Step-by-step explanation:
I just did it
Step-by-step explanation:

Answer:
C
Step-by-step explanation:
the buyer will get some amount of money left while the seller gets profit as well
Answer:
X= blue tiles
Y = red tiles
X/y = 4/21
X+y= 425
Y= 357 tiles
X= 68 tiles
Step-by-step explanation:
red and blue ceramic tiles are laid according to a pattern.
The pattern= every 21 red tiles used, 4 blue tiles are used
Total number of tiles used = 425 tiles
X= blue tiles
Y = red tiles
X/y = 4/21
X+y= 425
21x= 4y
X= 4y/21
X+y= 425
4y/21 + y = 425
25y= 425(21)
Y=( 425*21)/25
Y= 357 tiles
X= 4y/21
X= (4*357)/21
X= 1428/21
X= 68 tiles