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OTI365 - NTSE - X Standard
NTSE Mental Ability Test - Number Test Important Questions with Answer

Mental Ability Test - Number Test

Exam Duration: 45 Mins Total Questions : 30

1 )

On a week day, Rahul went to Mumbai. His mother remembers that he went after Monday but before Thursday. And Rahul remembers that he went after Tuesday but before Friday. On which day did Rahul actually go to Mumbai?

(a)
Wednesday
(b)
Friday
(c)
Thursday
(d)
none of these

Solution :

According to Rahul's mother, he went to Mumbai either Tuesday or Wednesday and according to Rahul he went to Mumbai either Wednesday or Thursday. The only common day they both remember is Wednesday.So the answer will be Wednesday

2 )

Study the following series carefully and answer the following questions.
@ I 9 Q R 6 U H 3 Z 7 * F 4 ! J 2 E A T B % M P 5 W 8 V # G $ Y D
How many such consonants are there in the above arrangement, each of which is immediately preceded by a number but not immediately followed by a number?

(a)
One
(b)
two
(c)
Three
(d)
four

Solution :

The consonant satisfying the given condition can be seen in bold as follows.
@ I 9 Q R 6 V H 3 Z 7 * F 4 ! J 2 E A T B % M P 5 W 8 V # G $ Y D

3 )

In a class, Pankaj's rank is 11th from the top and 24th from the bottom. How many students are there in the class?

(a)
35
(b)
34
(c)
36
(d)
30

Solution :

Number of students in the class:
11 + 24 - 1 = 34

4 )

In a class, Rome's rank 8th from the bottom and Sumit's rank is 16th from the top. The number of students between Roma and Sumit is 4.
How many students are there in the class?

(a)
28
(b)
30
(c)
29
(d)
31

Solution :

Number of students in the class:
Rorna's Rank (=8)+ Sumit's Rank (16)+ Number of students between Roma and Sumit (=(4)= 28)

5 )

In a row of thirty five children, Mohan is 19th from the left and Sohan is 23rd from right. Rohan is sitting exactly between them, then what will be Rohan's position from left?

(a)
11th
(b)
10th
(c)
16th
(d)
None of these

Solution :

Rohan's position from the right is
(19 + 23)$\div $2 = 21 -1 = 20.
So he is 16th from the left.

6 )

Sourabh remembers that his father's birthday is after 21st March but before 24th March. His sister Sunidhi remembers that her fa~her's birthday is after 22nd but
before 25th. What is the exact date of their father's birthday?

(a)
23rd
(b)
24th
(c)
20th
(d)
None of these

Solution :

Sourabh remembers that after 21 but before 24 meaning it is either 22 or 23 and his sister Sunidhi remembers that after 22 but before 25 meaning either 23 or 24. One common day is 23rd so the Answer will be =23rd

7 )

Ragav remembers that his brother Monu's anniversary is after 16thbut before 20thand Ragav's brother Monu remembers that his anniversary is after 17thbut before
21st.Monu's wife remembers that her anniversary is not on Wednesday. If the first day of the month is Saturday. What is the day of Monu's anniversary?

(a)
18^th
(b)
17^th
(c)
19^th
(d)
Data inadequate

Solution :

Ragav remembers 17, 18 and 19 and Monu remembers 18 and 19 and Wednesday will come on 18th.So the Answer will be 19th.

8 )

If 7th of July is Sunday, which of the following will be the day of the month?

(a)
Wednesday
(b)
Friday
(c)
Monday
(d)
Saturday

Solution :

There are 31 days in July, so 28th July will be Sunday. And 31st July will be Wednesday.

9 )

Which is the number that comes next in the sequence: 0,6,24,60,120,210?

(a)
240
(b)
290
(c)
336
(d)
504

Solution :

Clearly, the gi en series is
1³-1,2³ -2,3³ -3, 4³ -4,5³ - 5,6³ -6.
ஃ Next number = 7³ -7 = 343 -7 = 336

10 )

2,5,9, (...), 20, 27

(a)
14
(b)
16
(c)
18
(d)
24

Solution :

The pattern is +3, +4, ...
ஃ Missing number = 9 + 5 = 14

11 )

5,9,17,29,45,(...)

(a)
60
(b)
65
(c)
68
(d)
70

Solution :

The pattern is +4, +8, + 12, + 16, ...
ஃ Missing number = 45 + 20 = 65

12 )

196,169,144,121,80

(a)
80
(b)
121
(c)
169
(d)
196

Solution :

The sequence is (14)², (13)², ( 2)², (11)², (10)².
So, 80 is wrong and must be replaced by (10)² i.e. 100

13 )

1,2,4,8,16,32,64,96

(a)
4
(b)
32
(c)
64
(d)
96

Solution :

Each term of the series is obtained by multiplying the preceding term by 2
So, 96 is wrong and must be replaced by (64 x 2) i.e. 128

14 )

8,10, 14,18, ...., 34, 50,66

(a)
28
(b)
27
(c)
26
(d)
25

15 )

7,15,32, ....,138,281.

(a)
57
(b)
67
(c)
77
(d)
87

16 )

0.5,1.5,4.5,13.5,(...)

(a)
45.5
(b)
39.5
(c)
30.5
(d)
40.5

Solution :

Each term of the series is obtained By multiplying the preceding term by 3.
ஃ Missing number = 13.5 x 3 =40.5.

17 )

19,2,38,3,114,4,( .....)

(a)
228
(b)
256
(c)
352
(d)
456

Solution :

The sequence is a combination of two series:
I. 19,38, 114,(...) and 11. 2, 3,4
The pattern followed in 1 is x2, x3, ...
ஃ Missing number = 144 x 4 = 456.

18 )

66,36,18, (.....)

(a)
3
(b)
6
(c)
8
(d)
9

Solution :

Each number in the series is the product of the digits of the preceding number.
Thus, 6 x 6 = 36, 3 x 6 = 18 and so on.
ஃ Missing number = 1 x 8 = 8.

19 )

3,6,5,20,7,42,9,( .....)

(a)
54
(b)
60
(c)
66
(d)
72

Solution :

The sequence is a combination of two series:
I,3,5,7,9 and II. 6,20,42, (.....)
The pattern followed in II is + 14, + 22, ...
ஃ Missing number = 42 + 30 = 72.

20 )

34,18,10,6,4,( .....)

(a)
0
(b)
1
(c)
2
(d)
3

Solution :

Each term is divided by 2 and then increased by 1 to obtain the next term.
ஃ Missing term = (4 + 2) + 1 = 3.

21 )

In each of the following questions, one term in the number series is wrong. Find out the wrong term
380,188,92,48,20,8,2

(a)
188
(b)
92
(c)
48
(d)
20

Solution :

Each term in the series is four more than two times the next term. 0,48 is wrong and must be replaced by (20 x 2 +4) i.e.44.

22 )

6,7,9,13,21, ......

(a)
25
(b)
29
(c)
37
(d)
32

23 )

In each of the following questions, one number is wrong in the series. Find out the wrong number
376,188,88,40,16,4,-2

(a)
4
(b)
16
(c)
40
(d)
188

24 )

In each of the following questions, one number is wrong in the series. Find out the wrong number
701,348,173,85,41,19,8

(a)
173
(b)
41
(c)
19
(d)
348

25 )

In the following number series, one of the numbers does not fit into the series. Find the wrong number
1788,892,444,220, 112,52,24

(a)
52
(b)
112
(c)
220
(d)
444

26 )

In the following number series, one of the numbers does not fit into the series. Find the wrong number
10,12,28,90,368,1840,11112

(a)
1840
(b)
368
(c)
90
(d)
28

27 )

In each of the following one number is wrong in the series. Find out the wrong number in each case
1,2,6,24,120,620,5040

(a)
5040
(b)
620
(c)
120
(d)
24

28 )

In each of the following one number is wrong in the series. Find out the wrong number in each case
49,56,64,71,81,90,100,110

(a)
56
(b)
64
(c)
71
(d)
81

29 )

In each of the following questions, a number series is given. After the series below it in the next line, a number is given followed by (a), (b), (c), (d) and (e). You have to complete the series starting with the number given following sequence of the given series. Then, answer the questions given below it