Answer
a) $54$ tiles
b) $48$ yellow tiles
Work Step by Step
a) Table $1$ below shows the relationship between number of orange tiles and the total number of tiles in each figure.
Table $1$ also shows that when there are $24$ orange tiles, there will be a total of $54$ tiles.
b) Table $2$ below shows the relationship between number of blue tiles and the number of yellow tiles in each figure.
Extending the pattern in Table $2$, if there are $24$ blue tiles, the number of yellow tiles is
$$
24(2)=48\text{ yellow tiles}
.$$
