Rebecca is laying a tile in her bathroom.She needs 4 black tiles for every 16 white tiles.How many black tiles are needed if she uses 128 white tiles

Question

This a word problem for ratio and proportion

Answer 1

Ratio: 4 is to 16 as x is to 128

4:16::x:128

 

16x = 4(128)

x = 4(128)/16

 

Solve for x

Answer 2

b represents the number of black tiles

4 : 16 :: 128 : b     proportion

4b = 16(128)         product means/extremes

 

Can you solve for b?