Mental Ability — Pack 10

Question 1

The number series 1, 4, 9, 16, 25, ___ — next number is:

Accepted Answer

36 — This is a series of perfect squares: 1², 2², 3², 4², 5², 6² = 36.

Answer

30

Answer

49

Answer

64

Question 2

A's father's sister is A's:

Accepted Answer

Aunt — Paternal aunt.

Answer

Mother

Answer

Grandmother

Answer

Sister

Question 3

(3²)³ equals:

Accepted Answer

3⁶ — (aᵐ)ⁿ = aᵐⁿ; 3⁶ = 729.

Answer

3⁵

Answer

3⁸

Answer

3⁹

Question 4

Surface area of sphere r=7:

Accepted Answer

616 — 4πr²=4×22/7×49=616.

Answer

308

Answer

1232

Answer

154

Question 5

If 2x − 7 = 11, then x =

Accepted Answer

9 — 2x = 18 → x = 9.

Answer

6

Answer

7

Answer

8

Question 6

Euler's number e:

Accepted Answer

~2.71828 — ~2.71828.

Answer

~3.14

Answer

~1.618

Answer

~1.414

Question 7

Probability: drawing red card:

Accepted Answer

1/2 — 26/52=1/2.

Answer

1/4

Answer

1/13

Answer

1/26

Question 8

The next term in the sequence 2, 6, 12, 20, 30, ... is:

Accepted Answer

42 — Differences 4, 6, 8, 10, 12 → next = 30 + 12 = 42 (n(n+1)).

Answer

36

Answer

40

Answer

48

Question 9

AP — sum of first n terms:

Accepted Answer

Both equivalent — Sn = n/2[2a + (n-1)d] = n/2[a + l] where l is last term.

Answer

n/2[2a + (n-1)d]

Answer

n(a+l)

Answer

n²

Question 10

A sum triples at SI in 10 years. Rate of interest:

Accepted Answer

20% — SI = 2P; 2P = P·R·10/100 → R = 20%.

Answer

10%

Answer

15%

Answer

25%

Question 11

The slope of a line parallel to x-axis is:

Accepted Answer

0 — Horizontal line has zero slope; vertical line has undefined slope.

Answer

1

Answer

Undefined

Answer

Infinity

Question 12

In code: 639 = 'earth is green', 32 = 'green colour', 265 = 'colour is beauty'. Which digit means 'beauty'?

Accepted Answer

2 — Common digit between '639' and '265' for shared word 'is' → 6. Common between '32' and '265' for 'colour' → 2. Wait — '32' shares with '265' via... let me re-derive: 639 (earth, is, green) ∩ 32 (green, colour) shared word green → digit 3 or 6 or 9 ∩ 3 or 2 = 3. So green=3. 32 has 'green colour' → 3=green, 2=colour. 265 (colour is beauty) has 2,6,5. 2=colour, then 6=is (from 639 ∩ 265 sharing 'is'), so 5=beauty. Answer: 5 (D).

Answer

3

Answer

6

Answer

5

Question 13

Ranking: 15 students. Priya 8th from front. From back?

Accepted Answer

8 — In a line of N people, (rank from front) + (rank from back) = N + 1. So rank from back = 15 − 8 + 1 = 8.

Answer

7

Answer

9

Answer

6

Question 14

A point (−3, 4) lies in which quadrant?

Accepted Answer

II — Quadrant II: x negative, y positive.

Answer

I

Answer

III

Answer

IV

Question 15

Segment:

Accepted Answer

Region between chord and arc — Bounded by chord and arc.

Answer

Sector

Answer

Triangle

Answer

Tangent

Question 16

Five consecutive odd numbers sum 45. Smallest:

Accepted Answer

5 — Sum = 5×middle = 45. Middle 9. Smallest 5.

Answer

7

Answer

9

Answer

3

Question 17

Curved surface area of a cylinder (radius r, height h) is:

Accepted Answer

2πrh — CSA = 2πrh; total SA (closed) = 2πr(r+h).

Answer

πr²

Answer

2πr(r+h)

Answer

πr²h

Question 18

Solve: 2x − 5 = 11

Accepted Answer

8 — 2x = 16 → x = 8.

Answer

3

Answer

6

Answer

10

Question 19

How many seconds in 2 hours 15 minutes?

Accepted Answer

8100 — 2h 15min = 2×3600 + 15×60 = 7200 + 900 = 8100 s.

Answer

7200

Answer

8400

Answer

9000

Question 20

Simple interest doubles in 10 yrs. Triples in:

Accepted Answer

20 — Linear: (triple-1) vs (double-1) years.

Answer

15

Answer

25

Answer

30

Question 21

If two dice are rolled, probability of sum = 7 is:

Accepted Answer

1/6 — 6 combinations for sum 7: (1,6)(2,5)(3,4)(4,3)(5,2)(6,1) = 6/36 = 1/6.

Answer

1/9

Answer

1/12

Answer

5/36

Question 22

tan 0° =

Accepted Answer

0 — tan 0° = sin 0°/cos 0° = 0/1 = 0.

Answer

1

Answer

∞

Answer

−1

Question 23

Reflex angle:

Accepted Answer

More than 180 — More than 180°, less than 360°.

Answer

Less than 90

Answer

Exactly 180

Answer

Any

Question 24

GP — nth term:

Accepted Answer

a · r^(n-1) — Geometric progression. Sum of n terms: a(rⁿ - 1)/(r-1). Infinite sum if |r|<1: a/(1-r).

Answer

a + (n-1)d

Answer

a/r

Answer

n·a

Question 25

Volume of a cube is 64 cm³. Its total surface area is:

Accepted Answer

96 cm² — Side = ³√64 = 4 cm. TSA = 6 × 16 = 96 cm².

Answer

8 cm²

Answer

32 cm²

Answer

64 cm²

Mental Ability — Pack 10