ExamAdept

What is the cost painting the two adjacent walls of a hall at Rs. 5 per m² which has no windows or doors?
I.	The area of the hall is 24 sq. m.
II.	The breadth, length and height of the hall are in the ratio of 4 : 6 : 5 respectively.
III.	Area of one wall is 30 sq. m.

A:

I only

B:

II only

C:

III only

D:

Either I or III

Answer: C

From II, let l = 4x, b = 6x and h = 5x.

Then, area of the hall = (24x²) m².

From I. Area of the hall = 24 m².

From II and I, we get 24x² = 24 x = 1.

l = 4 m, b = 6 and h = 5 m.

Thus, area of two adjacent walls = [(l x h) + (b x h)] m² can be found out and so the cost of painting two adjacent walls may be found out.

Thus, III is redundant.

Correct answer is (C).

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What is the area of the given rectangle?
I.	Perimeter of the rectangle is 60 cm.
II.	Breadth of the rectangle is 12 cm.
III.	Sum of two adjacent sides is 30 cm.

A:

I only

B:

II only

C:

I and II only

D:

II and III only

Answer: E

From I and II, we can find the length and breadth of the rectangle and therefore the area can be obtained.

So, III is redundant.

Also, from II and III, we can find the length and breadth and therefore the area can be obtained.

So, I is redundant.

Correct answer is "II and either I or III".

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What is the area of rectangular field?
I.	The perimeter of the field is 110 metres.
II.	The length is 5 metres more than the width.
III.	The ratio between length and width is 6 : 5 respectively.

A:

I and II only

B:

Any two of the three

C:

All I, II and III

D:

I, and either II or III only

Answer: B

I. 2(l + b) = 110 l + b = 55.

II. l = (b + 5) l - b = 5.

III.	l	=	6	5l - 6b = 0.
	b		5

These are three equations in l and b. We may solve them pairwise.

Any two of the three will give the answer.

Correct answer is (B).

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What is the area of a right-angled triangle?
I.	The perimeter of the triangle is 30 cm.
II.	The ratio between the base and the height of the triangle is 5 : 12.
III.	The area of the triangle is equal to the area of a rectangle of length 10 cm.

A:

I and II only

B:

II and III only

C:

I and III only

D:

III, and either I or II only

Answer: A

From II, base : height = 5 : 12.

Let base = 5x and height = 12x.

Then, hypotenuse = (5x)² + (12x)² = 13x.

From I, perimeter of the triangle = 30 cm.

5x + 12x + 13x = 30 x = 1.

So, base = 5x = 5 cm, height = 12x = 12 cm.

Area =		1	x 5 x 12	cm²	= 30 cm².
		2

Thus, I and II together give the answer.

Clearly III is redundant, since the breadth of the rectangle is not given.

Correct answer is (A).

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What is the area of the hall?
I.	Material cost of flooring per square metre is Rs. 2.50
II.	Labour cost of flooring the hall is Rs. 3500
III.	Total cost of flooring the hall is Rs. 14,500.

A:

I and II only

B:

II and III only

C:

All I, II and III

D:

Any two of the three

Answer: C

I. Material cost = Rs. 2.50 per m²

II. Labour cost = Rs. 3500.

III. Total cost = Rs. 14,500.

Let the area be A sq. metres.

Material cost = Rs. (14500 - 3500) = Rs. 11,000.

	5A	= 11000 A =		11000 x 2		= 4400 m².
	2			5

Thus, all I, II and III are needed to get the answer.

Correct answer is (C).

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Questions for: Area