Question

9. The area of the ring between two concentric circles is 3168 cm2. Find the radii of the two
circles if their difference is 28 cm.

the answer is 32 cm and 4 cm .
make sure the answer from your process is this only
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Answer 1

Answer:

ANSWER

Let two radius are 'x' and 'y', so,

x+y=42....(1)

and

x−y=28.....(2)

Now adding (1) and (2), we get

2x=70

x=35

Putting in (1)

35+y=42

y=7

Therefore, radius of two concentric circles are 35 cm and 7 cm.

Answer 2

Answer:

ANSWER

Let two radius are 'x' and 'y', so,

x+y=42....(1)

and

x−y=28.....(2)

Now adding (1) and (2), we get

2x=70

x=35

Putting in (1)

35+y=42

y=7

Therefore, radius of two concentric circles are 35 cm and 7 cm