11 Plus Exams Forum

Please help - how do we work out the following:
1. A tiled floor is covered with 30 square tiles. The longest side of the floor is made by 6 tiles.
What is the perimeter of this floor if the tiles are 209cm squares?

2. If you took all of the tiles and laid them side by side...what would be the perimeter of the shape you had made?

Thankyou

cbiscette wrote:Sorry everyone for the type - should be 20cm squares not 209cm as posted

1)Must be 6 by 5 shape so one side would be 1m and the other side would be 1.2m so the perimeter would be 4.4m.

2) if laid side by side the perimeter would be 62*0.2m = 12.4m (hope that's right - sone in my head as no calculator at work) - it is a shap 20cm by 30*0.2m= 6m long

Hi thanks for your response but need some more info, please

What info do you need?

Perimeter of a rectangle = 2 (length + width)

a) Perimeter of the rectangle formed will be

length = 6 tiles * 20 cm
width = 5 tiles * 20 cm

= 2 ( 120 cm + 100 cm) = 2 ( 220 cm) = 440 cm

b) Laying the tiles in a row would mean the shape would become as below:

length = 30 tiles * 20 cm
width = 1 tiles * 20 cm

So, perimeter = 2 ( 600 cm + 20 cm) = 2 ( 620 cm) = 1240 cm

Hope this helps.

P.S: Note that there is a difference between "x metres square" and "x square metres".

Hi - Thank you very much for your help - very helpful...
most appreciated