Verbal Reasoning - Mental Ability Questions

We know that, any decimal number when multiplied by the multiples of 10, the decimal point moves to right the number of zeroes in the multiplying number.

For example :: 

0.0410 x 100 = 4.10 (Number of zeros in 100 are 2. So, the decimal point in 0.0410 moves two places to the right and becomes 4.10.)

Similarly, here in the option C) 5.008 x 10^3 kms it makes 5008 kms as the number of zeros in 10^3  i.e,  1000 are 3 and 5.008 becomes 5008.

Absolute value of a number :

It means that the distance of a number from 0 on a number line. 

Here absolute value of 9 is that on a number line 9 is 9 units away from 0. Hence its absolute value is 9. Similarly, absolute value of -9 means -9 is also 9 units away from the 0 on number line. Hence, absolute value of -9 is also 9.

Hence, the absolute value of 9 is 9.

It is given that the first digit is 1/3 of the second. There are 3 such possibilities

1)1 and 3
2)2 and 6
3)3 and 9
Now, the third digit is the sum of the first and second digits.
1)1 + 3 = 4
2)2 + 6 = 8
3)3 + 9 = 12
It is clear that option 3 is not possible. So we are left with only two options. Also, the last digit is three times the second, which rules out the second option.

Hence, the answer is 1349.