## Numerical Ability

#### Numerical Ability

1. Find the missing group of letters in the following series: BC, FGH, LMNO

1. NA

##### Correct Option: B

NA

1. Given that a and b are integers and a + a2b3 is odd, which one of the following statements is correct?

1. NA

##### Correct Option: D

NA

1. The perimeters of a circle, a square and an equilateral triangle are equal. Which one of the following statements is true?

1. The most symmetric figure will have the largest area.
Hence, circle will be the right answer.

##### Correct Option: A

The most symmetric figure will have the largest area.
Hence, circle will be the right answer.

1. From the time the front of a train enters a platform, it takes 25 seconds for the back of the train to leave the platform, while travelling at a constant speed of 54 km/h. At the same speed, it takes 14 seconds to pass a man running at 9 km/h in the same direction as the train. What is the length of the train and that of the platform in meters, respectively?

1. Train speed (ST) = 54 km/h
Time = 25 sec for travelling length of train and length of platform
Man speed (SM) = 9 km/h
Speed of train to man = 45 km/h
Time = 14 sec
So, length of train = time × speed

 = 14 × 45 × 5 18

Length of train (L T) = (35 × 5 m) = 175 m
Length of platform (L) + length of train (L T) = speed × time
 = 54 × 5 × 25 = 15 × 25 = 375m 18

∴ Length of platform (L) = 375 - 175 = 200 m

##### Correct Option: D

Train speed (ST) = 54 km/h
Time = 25 sec for travelling length of train and length of platform
Man speed (SM) = 9 km/h
Speed of train to man = 45 km/h
Time = 14 sec
So, length of train = time × speed

 = 14 × 45 × 5 18

Length of train (L T) = (35 × 5 m) = 175 m
Length of platform (L) + length of train (L T) = speed × time
 = 54 × 5 × 25 = 15 × 25 = 375m 18

∴ Length of platform (L) = 375 - 175 = 200 m

1. For integers a, b and c, what would be the minimum and maximum values respectively of a + b + c if log|a| + log|b| + log|c| = 0

1. log |a| + log |b| + log |c| = 0
It is possible only,
when |a|, |b| and |c| all are equal to 1.
∴ a, b, c may be ±1, ±1, ±1 respectively.
Now for minimum value of all thr ee will be negative.
∴ minimum value = - 3
and maximum value of all three will be positive.
∴ maximum value = +3

##### Correct Option: A

log |a| + log |b| + log |c| = 0
It is possible only,
when |a|, |b| and |c| all are equal to 1.
∴ a, b, c may be ±1, ±1, ±1 respectively.
Now for minimum value of all thr ee will be negative.
∴ minimum value = - 3
and maximum value of all three will be positive.
∴ maximum value = +3