Mental Ability — Pack 07

Question 1

Simple interest on ₹1000 at 10% per annum for 2 years is:

Accepted Answer

₹200 — SI = PRT/100 = 1000×10×2/100 = 200.

Answer

₹100

Answer

₹220

Answer

₹300

Question 2

A and B play football and cricket. B and C play cricket and hockey. A and D play basketball and football. C and D play hockey and basketball. Who plays football, basketball and hockey?

Accepted Answer

D — D plays basketball (with A and C) and hockey (with C). D also plays football? A and D play basketball and football → D plays football too. So D plays all three.

Answer

A

Answer

B

Answer

C

Question 3

12.5 + 12.3 minus you (12.5 ÷ 12.3) ratio (a:b form):

Accepted Answer

5:8 — OCR garbled; answer per standard key 5:8.

Answer

11:8

Answer

8:1

Answer

8:5

Question 4

Series: 5, 6, 9, 14, 21, ?

Accepted Answer

30 — Diff 1,3,5,7,9; 21+9=30.

Answer

28

Answer

32

Answer

35

Question 5

Ratio of milk to water 5:3. Add 4L water, ratio 5:4. Initial milk:

Accepted Answer

20L — 5x/(3x+4) = 5/4. 20x = 15x+20. x=4. Milk = 20L.

Answer

10L

Answer

12L

Answer

15L

Question 6

A cube of side 1 cm has volume 1 cm³. A cube of side 2 cm has volume:

Accepted Answer

8 cm³ — V = s³ = 2³ = 8 cm³ (volume scales with cube of linear dimension).

Answer

2 cm³

Answer

4 cm³

Answer

6 cm³

Question 7

Find odd: 2, 3, 5, 7, 11, 15

Accepted Answer

15 — 15 is composite; rest primes.

Answer

2

Answer

3

Answer

11

Question 8

Time taken by a 180 m long train running at 54 km/hr to cross a man on the platform:

Accepted Answer

12 seconds — 54 km/hr = 15 m/s. Time = 180/15 = 12 seconds.

Answer

4 seconds

Answer

8 seconds

Answer

16 seconds

Question 9

What is the primary purpose of an ANOVA test?

Accepted Answer

Compare the means of two or more groups — ANOVA (Analysis of Variance) tests whether the means of two or more groups differ significantly.

Answer

Determine the correlation between two variables

Answer

Calculate the standard deviation of a sample

Answer

Test the hypothesis of independence between two categorical variables

Question 10

Two angles of a triangle are 45° and 55°. The third angle is:

Accepted Answer

80° — 180 − 45 − 55 = 80°.

Answer

70°

Answer

75°

Answer

90°

Question 11

Analogy: Hour : Minute :: Minute : ?

Accepted Answer

Second — Second.

Answer

Hour

Answer

Clock

Answer

Time

Question 12

Book : Library :: Tree : ?

Accepted Answer

Forest — Book collection = library; tree collection = forest.

Answer

Branch

Answer

Leaf

Answer

Fruit

Question 13

Interior angles of octagon sum:

Accepted Answer

1080° — (8-2)180=1080.

Answer

720°

Answer

900°

Answer

1440°

Question 14

Analogy: Brave : Coward :: Humble : ?

Accepted Answer

Arrogant — Opposite pair.

Answer

Modest

Answer

Shy

Answer

Honest

Question 15

Complete the series: BJF, DKH, FMJ, HPL, ___

Accepted Answer

JQO — BJF, DKH, FMJ, HPL — 1st letter +2 each (B→D→F→H→J). 2nd letter +1,+2,+3,+4 (J→K→M→P→T… variants). 3rd letter +2 each (F→H→J→L→N). Accepted PSC key: JQO.

Answer

KRM

Answer

JON

Answer

KON

Question 16

Compound interest on ₹10,000 at 10% p.a. for 2 years (annual compounding):

Accepted Answer

₹2100 — A = 10000×1.21 = 12100; CI = 2100.

Answer

₹2000

Answer

₹2200

Answer

₹2500

Question 17

Area of an equilateral triangle of side 'a' is:

Accepted Answer

(√3/4)a² — Area of equilateral triangle = (√3/4)·side².

Answer

a²

Answer

(1/2)a²

Answer

πa²

Question 18

Slope of line through (x₁,y₁) and (x₂,y₂):

Accepted Answer

(y₂-y₁)/(x₂-x₁) — Rise over run. Parallel lines: equal slopes. Perpendicular: product = -1.

Answer

y₂-y₁

Answer

x₂-x₁

Answer

y/x

Question 19

Diagonal of cube side a:

Accepted Answer

a√3 — a√3.

Answer

a√2

Answer

a√5

Answer

2a

Question 20

A invests ₹5000 for 12 months, B ₹8000 for 6 months. Profit ratio:

Accepted Answer

5:4 — 5000×12 : 8000×6 = 60000 : 48000 = 5:4.

Answer

5:8

Answer

1:1

Answer

10:8

Question 21

A clock seen through a mirror when time is 7 o'clock shows:

Accepted Answer

5:00 — Mirror image of 7 o'clock = 5:00 (reflection inverts left-right).

Answer

3:20

Answer

4:20

Answer

7:00

Question 22

Which letter is 8th to left of 17th from left?

Accepted Answer

9th letter (I) — 17-8 = 9th letter = I.

Answer

9th

Answer

8th

Answer

J

Question 23

Coefficient of x² in (1+x)⁵:

Accepted Answer

10 — Binomial theorem: 5C2 = 10. (1+x)ⁿ = ΣnCr·xr.

Answer

5

Answer

20

Answer

1

Question 24

A right triangle has one angle of:

Accepted Answer

90° — Right triangle has a 90° angle; other two sum to 90°.

Answer

45°

Answer

60°

Answer

120°

Question 25

The sum of first n even natural numbers is:

Accepted Answer

n(n+1) — 2+4+6+...+2n = 2·(1+2+...+n) = 2·n(n+1)/2 = n(n+1).

Answer

n²

Answer

(n+1)/2

Answer

n·n/2

Mental Ability — Pack 07