Susan is buying three different colors of tiles for her kitchen floor. she is buying 25 more red tiles than beige tiles, and three times as many navy-blue tiles as beige tiles. if susan buys 435 tiles altogether, how many tiles of each color does she buy?

Let us assume that the number of beige tiles bought by Susan = B
Number of red tiles bought by Susan = R
Number of navy-blue tiles bought by Susan =N
Number of tiles bought altogether = 435
Now from the given question we know:
Number of red tiles bought is 25 more than the number of beige tiles.
So
 R = 25 + B
Number of navy blue tiles bought is 3 times that of the number of beige tile bought
So
N = 3B
We already know that the total number of tiles bought is 435
Hence
B + R + N = 435
B + (25 + B) + 3B = 435
5B + 25 = 435
5B = 435 -25
5B = 410
B = 82
R = 25 + B
   = 25 + 82
   = 107
N = 3B
   = 3 * 82
   = 246
So the number of Beige tiles  bought by Susan = 82
The number of red tiles bought by Susan = 107
The number of navy-blue tiles bought by Susan = 246