Question

A circular tabletop has a diameter of 2.1 m.

a) What is the area?
b) The table is to be painted. One tin of paint can cover an area of 1.75 m² and cost 5.50 dollars.
ii)How any tins of paint must be bought?
iii) How much will it cost for materials and labour is 2/3 the cost of materials?

Answer 1

a=3.46 (2dp) b(ii)=2

Explanation:

a)

πr²=area

2.1/2 = 1.05 as the radius

1.05² x π= 3.46 (2dp)

b)

3.46/1.75= 1.98

1.98 can be changed into two

∴ 2 tins will be needed

Answer 2

Explanation:

Area of Circle:

a) Diameter = 2.1 m

r = 2.1 ÷ 2 = 1.05 m

Area = πr²

= 3.14 * 1.05 * 1.05

= 3.46 = 3.5 m²

b) To find the number of paint tins, divide the area of table top by 1.75 m²

Number of tins = 3.5 ÷ 1.75

= 2 tins

c) Cost of 1 tin = $ 5.50

Cost of 2 tin = 2 *5.50

= $ 11

`\sf d) Cost\ of \ labour = (2)/(3) * 11`

= $ 7.30