If a bathroom wall is covered by 160 tiles which are 15cm by 15cm, how many 10cm by 10cm tiles are needed to cover the  same wall.

Expert Answers
embizze eNotes educator| Certified Educator

Each 15x15 tile covers `"225cm"^2` ; since there are 160 tiles the tiled area of the bathroom wall is `225*160=36000"cm"^2` .

If we are to cover the same wall with 10x10 tiles, we need to find how many tiles are required to cover the same area. Each 10x10 tile covers `100"cm"^2` .

The number of tiles required is the total area divided by the area per tile: `36000/100=360` .


The total number of 10cm x 10cm tiles required is 360