1.1. The diagram shows a wall in the shape of a trapezium.

Karen is going to cover this part of the wall with tiles.
Each tile is rectangular, 15 cm by 7.5 cm.

Tiles are sold in packs.
There are 9 tiles in each pack.

Karen divides the area of this wall by the area of a tile to work out an estimate for the number of tiles she needs to buy.

Use Karen's method to work out the estimate for the number of packs of tiles she needs to buy.

1.2. Karen is advised to buy 10% more tiles than she estimated. Buying 10% more tiles will affect the number of the tiles Karen needs to buy.

She assumes she will need to buy 10% more packs of tiles.

Is Karen's assumption correct?
You must show your working.