number system Model Questions & Answers, Practice Test for ibps so prelims 2023

Answer: (a)

Given series is-

$1/4 + 1/5 - 1/6 - 1/4 - 1/5 + 1/6 + 1/4 + 1/5 - 1/6 - 1/4 - 1/5 + 1/6$ + - - -

These 6 terms are repeating which are resulting to zero.

so 1st 42 terms of this series will result is zero and after that series will be upto 47 terms –

⇒$1/4 + 1/5 - 1/6 - 1/4 - 1/5 ⇒ - 1/6$

So, option (b) is correct.

Answer: (b)

From the above table we can see that the power 73 is of the form 4x + 1

Therefore the unit digit in $7^73$ = 7

Answer: (b)

Let the numbers be x, y and z. Then,

x + y = 10 ...(1)

y + z = 19 ...(2)

z + x = 21 ...(3)

Adding (1), (2) and (3), we get

2 (x + y + z) = 50

x + y + z = 25

x = 25 – 19 = 6;

y = 25 – 21 = 4;

z = 25 – 10 = 15

Product = 6 × 4 × 15 = 360

Answer: (b)

Divisor = $r_1 + r_2 - r_3$ = 35 + 30 – 20 = 45

Answer: (d)

d [d {d (12)}] = d [d (6)]

(q positive integer divisor of 12 = 1, 2, 3, 4, 6, 12)

= d (4) (q positive integer divisor of 6 = 1, 2, 3, 6)

= 3 (q positive integer divisor of 4 = 1, 2, 4)