Aptitude - Decimal Fraction

Exercise : Decimal Fraction - General Questions
1.

Evaluate : (2.39)2 - (1.61)2
2.39 - 1.61
2
4
6
8
Answer: Option
Explanation:
Given Expression = a2 - b2 = (a + b)(a - b) = (a + b) = (2.39 + 1.61) = 4.
a - b (a - b)

2.
What decimal of an hour is a second ?
.0025
.0256
.00027
.000126
Answer: Option
Explanation:
Required decimal = 1 = 1 = .00027
60 x 60 3600

3.

The value of (0.96)3 - (0.1)3 is:
(0.96)2 + 0.096 + (0.1)2
0.86
0.95
0.97
1.06
Answer: Option
Explanation:
Given expression
= (0.96)3 - (0.1)3
(0.96)2 + (0.96 x 0.1) + (0.1)2
= a3 - b3
a2 + ab + b2
= (a - b)
= (0.96 - 0.1)
= 0.86

4.
The value of 0.1 x 0.1 x 0.1 + 0.02 x 0.02 x 0.02 is:
0.2 x 0.2 x 0.2 + 0.04 x 0.04 x 0.04
0.0125
0.125
0.25
0.5
Answer: Option
Explanation:
Given expression = (0.1)3 + (0.02)3 = 1 = 0.125
23 [(0.1)3 + (0.02)3] 8

5.
If 2994 ÷ 14.5 = 172, then 29.94 ÷ 1.45 = ?
0.172
1.72
17.2
172
Answer: Option
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