Decimal Fraction

Question:
The expression (11.98 x 11.98 + 11.98 x x + 0.02 x 0.02) will be a perfect square for x equal to:

[A].

0.02

[B].

0.2

[C].

0.04

[D].

0.4

Answer: Option C

Explanation:

Given expression = (11.98)2 + (0.02)2 + 11.98 x x.

For the given expression to be a perfect square, we must have

11.98 x x = 2 x 11.98 x 0.02 or x   = 0.04

Question: If 2994 ÷ 14.5 = 172, then 29.94 ÷ 1.45 = ?
[A].

0.172

[B].

1.72

[C].

17.2

[D].

172

Answer: Option C

Explanation:

29.94	=	299.4
1.45		14.5

=		2994	x	1		[ Here, Substitute 172 in the place of 2994/14.5 ]
		14.5		10

=	172
	10

= 17.2

Question:
3.87 – 2.59 = ?

[A].

1.20

[B].

1.2

[C].

1.27

[D].

1.28

Answer: Option D

Explanation:

3.87 – 2.59 = (3 + 0.87) – (2 + 0.59)

=		3 +	87		–		2 +	59
			99					99

= 1 +		87	–	59
		99		99

= 1 +	28
	99

= 1.28.

Question:
The correct expression of 6.46 in the fractional form is:

[A].

646

99

[B].

64640

1000

[C].

640

100

[D].

640

99

Answer: Option D

Explanation:

6.46  = 6 + 0.46  = 6 +	46	=	594 + 46	=	640	.
	99		99		99

Question: The least among the following is:
[A].

0.2

[B].

1 ÷ 0.2

[C].

0.2

[D].

(0.2)2

Answer: Option D

Explanation:

1 ÷ 0.2 =	1	=	10	= 5;
	0.2		2

0.2 = 0.222…;

(0.2)2 = 0.04.

0.04 < 0.2 < 0.22….<5.

Since 0.04 is the least, so (0.2)2 is the least.

Question:
The rational number for recurring decimal 0.125125…. is:

[A].

63

487

[B].

119

993

[C].

125

999

[D].

None of these

Answer: Option C

Explanation:

0.125125… = 0.125 =	125
	999

Question:
When 0.232323….. is converted into a fraction, then the result is:

[A].

1

5

[B].

2

9

[C].

23

99

[D].

23

100

Answer: Option C

Explanation:

0.232323… = 0.23 =	23
	99

Question:
The price of commodity X increases by 40 paise every year, while the price of commodity Y increases by 15 paise every year. If in 2001, the price of commodity X was Rs. 4.20 and that of Y was Rs. 6.30, in which year commodity X will cost 40 paise more than the commodity Y ?

[A].

2010

[B].

2011

[C].

2012

[D].

2013

Answer: Option B

Explanation:

Suppose commodity X will cost 40 paise more than Y after z years.

Then, (4.20 + 0.40z) – (6.30 + 0.15z) = 0.40

0.25z = 0.40 + 2.10

z =	2.50	=	250	= 10.
	0.25		25

X will cost 40 paise more than Y 10 years after 2001 i.e., 2011.

Question:
4.036 divided by 0.04 gives :

[A].

1.009

[B].

10.09

[C].

100.9

[D].

None of these

Answer: Option C

Explanation:

4.036	=	403.6	= 100.9
0.04		4

Question:
How many digits will be there to the right of the decimal point in the product of 95.75 and .02554 ?

[A].

5

[B].

6

[C].

7

[D].

None of these

Answer: Option B

Explanation:

Sum of decimal places = 7.

Since the last digit to the extreme right will be zero (since 5 x 4 = 20), so there will be 6 significant digits to the right of the decimal point.