TNPSC Group 1 Aptitude Questions and Answers in English - 1

Question: 1

The greatest number which can divide 1356, 1868 and 2764 leaving the same remainder 12 in each case is

(A) 64

(B) 124

(C) 156

(D) 260

Ans: A

Required number

= H.C.F. of (1356 - 12), (1868 - 12) and (2764 - 12)

= H.C.F. of 1344, 1856 and 2752 = 64.

Question: 2

A room is 4 m 37 cm long and 3 m 23 cm broad. It is required to pave the floor with minimum square slabs. Find the number of slabs required for this purpose.

(A) 381

(B) 391

(C) 431

(D) 485

Ans: B

Length = 437 cm

Breadth = 323 cm

The side of the square slab is the H.C.F of 437 and 323, i.e. 19 cm.

∴ Area of square slab = 19 cm × 19 cm = 361 cm2

The number of slabs = $${Area of the room} / {Area of the slab}$$ = $${437 × 323 cm^2} / {361cm^2}$$ = 391.

Question: 3

What is the smallest number which when increased by 3 is divisible by 16, 24, 30 and 32?

(A) 472

(B) 475

(C) 477

(D) 480

Ans: C

Required number = (L.C.M. of 16, 24, 30 and 32) - 3 = 480 - 3 = 477.

Question: 4

The H.C.F of 204, 1190 and 1445 is

(A) 17

(B) 18

(C) 19

(D) 20

Ans: A

204 = 22 × 3 × 17;

1190 = 2 × 5 × 7 × 17; 1445 = 5 × 172

∴ H.C.F. = 17.

Question: 5

The traffic lights at three different road crossings change after every 48 sec, 72 sec and 108 sec respectively. If they all change simultaneously at 8 : 20 : 00 hours, then they will again change simultaneously at

(A) 8 : 27 : 12 hours

(B) 8 : 27 : 24 hours

(C) 8 : 27 : 36 hours

(D) 8 : 27 : 48 hours

Ans: A

Interval of change = (LCM of 48, 72, 109) sec = 432 sec

∴ The light will change simultaneously after every 432 seconds,

i.e., 7 min 12 sec.

∴ Next simultaneously change will take place at 8 : 27 : 12 hours.

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