Diameter of a bangle is 7 cm. Thin strip of gold is to be fixed on this bangle, find the cost (in Rs.) for it at the rate of Rs.100 per 1 cm.

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Rs. 2500

Rs. 2200

Rs. 2000

Rs. 3500

answer is B.

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Detailed Solution

Concept- Here, we will calculate the total cost required to create the gold stripe that will be placed inside the bracelet. So that we may quickly determine the bangle's circumference, the diameter is provided to us. The entire cost can then be calculated by multiplying the circumference by the cost of fixing a thin gold strip per cm.
The diameter of the bangles is given as 7cm.
Question Image

So, the radius is calculated as

Then, the circle's circumference would be

2 πr

.
When we substitute the value of r, we obtain

\Rightarrow 2 \times π \times \frac{7}{2} cm

Thus, the bangle's circumference is 22 cm.
The cost to attach a thin gold strip to a bangle is now 100 per cm.
As a result, the cost for fixing a thin gold strip to a bracelet is equal to the bangle's circumference divided by the rate per cm.
So, the total cost =Rs.