Question

If a circular sheet of aluminium foil with diameter 40 cms Is cut into a smaller circles of radlus 5 cms each wal is ine ratio of the uncut to the cut portion?​

Answer 1

Answer:

uncut: cut = 5: 11

Step-by-step explanation:

for large circle,

A=$\frac{1}{4}$$\pi$d²

A=($\pi$ 40×40)/4

A= 400$\pi$ cm²

for small circle,

a=$\pi$r²

a= $\pi$ 5×5

a= 25$\pi$ cm²

no of circles= 400$\pi$/25$\pi$=16

But only 11 can fit.

∴ uncut=16-11= 5 and cut=11