Question Details

A wire would enclose an area of 1936 m2 , if it is bent into a square. The wire is cut into two pieces. The longer piece is thrice as long as the shorter piece. The long and the short pieces are bent into a square and a circle, respectively. Which of the following choices is closest to the sum of the areas enclosed by the two pieces in square meters?

Options

A

1096

B

1111

C

1243

D

2486

Correct Answer :

1243

Solution :

The correct answer is 1243.

First, we find the side length of the square that the wire would enclose if it were bent as a whole. Let a be the side length of the square. Given that the area of the square is 1936 m2, we have:

a2=1936

Solving for a by taking the square root:

a=1936=44 m

The total length of the wire is the perimeter of this square, which is:

Total length=4×a=4×44=176 m

The wire is cut into two pieces where the longer piece is thrice as long as the shorter piece. If we let the shorter piece be s and the longer piece be l, we have:

l=3s

Since the sum of the two pieces is the total length of the wire:

s+l=176

s+3s=176

4s=176

s=44 m

Therefore, the longer piece is:

l=3×44=132 m

Next, the longer piece of length 132 m is bent into a square. The side length anew of this new square is:

anew=1324=33 m

The area of this square is:

Areasquare=332=1089 m2

The shorter piece of length 44 m is bent into a circle. The circumference of this circle is 44 m, so the radius r is given by:

2×π×r=44

r=442×π=22π7 m

The area of this circle is:

Areacircle=π×r2π×72227×49=154 m2

Finally, we sum the two areas:

Total Area=Areasquare+Areacircle1089+154=1243 m2

This matches the correct option of 1243.

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