# Math Help - Diameter

1. ## Diameter

I've got a maths exam next week and i need to know how to work this question out for my revision so please could u show me:

The diameter of a table is 5.5 metres. A book claims that 50 people sat around the table. Assume each person needs 45 cm around th circumference of the table. is it possible for 50 people to sit around the table? show your working to explain your answer.

2. First find the circumference.

$\text{circumference}=2\pi\;r$

The diameter of the table is twice the radius.

$2r=5.5 \;\text{meters}$ so $r=2.75 \;\text{meters}$

and

$\text{circumference}=2\pi*r=2\pi*2.75=17.28\;\text {meters}$

And we know that $17.28\;\text{meters}*100=1728\;\text{cm}$

You need to fit 50 people with 45 cm per person. That's $50*45=2250\;\text{cm}$

Since $2250\geq 1728$, they will not fit, because you need at least 2250 cm and you only have 1728.