Aptitude - Surds and Indices - Discussion
Discussion Forum : Surds and Indices - General Questions (Q.No. 10)
10.
(0.04)-1.5 = ?
Answer: Option
Explanation:
| (0.04)-1.5 = |  |
4 |  |
-1.5 |
| 100 |
| = | |
1 | |
-(3/2) |
| 25 |
= (25)(3/2)
= (52)(3/2)
= (5)2 x (3/2)
= 53
= 125.
Discussion:
27 comments Page 2 of 3.
Maruthu said:
9 years ago
Please tell me the shortcuts in surds and indices.
Jayananda said:
7 years ago
How the minus sign disappeared from the fraction of 3/2?
RAVISHANKAR said:
7 years ago
It's reciprocal @Jayananda.
Monisha said:
7 years ago
@All
According to me, the solution is;
(0.04)^-1.5 { since 0.2*0.2=0.04}
= (0.2)^2*(-1.5),
=(0.2)^ -3,
=( 1/8) ^-3,
= 8^3 {since reciprocal changes the sign in power}
=512.
I used to solve it in a different method. But why am I not getting the answer? Please someone sorts this out.
According to me, the solution is;
(0.04)^-1.5 { since 0.2*0.2=0.04}
= (0.2)^2*(-1.5),
=(0.2)^ -3,
=( 1/8) ^-3,
= 8^3 {since reciprocal changes the sign in power}
=512.
I used to solve it in a different method. But why am I not getting the answer? Please someone sorts this out.
Chirag said:
7 years ago
No @Monisha.
Because on dividing 1 by 8 i.e. 1/8 doesn't give us 0.2. So, 1/8 is not equal to 0.2.
Because on dividing 1 by 8 i.e. 1/8 doesn't give us 0.2. So, 1/8 is not equal to 0.2.
Sabitha said:
7 years ago
0.2 is equal to 1/5 @Monisha.
Rakhi said:
7 years ago
How come -3/2 to 3/2?
x^-1 = (1/x) ^1.
x^-1 = (1/x) ^1.
Revanasidda said:
7 years ago
How -3/2 changes to 3/2?
By the basic law of indices, ie x^-1 can be written as 1/x.
By the basic law of indices, ie x^-1 can be written as 1/x.
(1)
Lunox said:
6 years ago
How did you get 4/100? Explain me.
Misbahul haque said:
6 years ago
How come (1/25)^3/25 = (25)^3/25? Explain this step.
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