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

Answer: (d)

Lowest number of set A = 280 5 – 4 = 52

Lowest number of other set = 52 × 2 – 71 = 33

∴ Required sum = 33 + 34 + 35 + 36 + 37 = 175

Answer: (a)

Use test of 11 after putting y = 5.

Answer: (c)

Let the two-digit number be

= 10x + y, where x > y

According to the question,

10x + y – 10y – x = 18

or, 9x – 9y = 18

or, 9(x – y) = 18

or, x – y = $18/9$ = 2 ...(i)

and, x + y = 12 ...(ii)

From equations (i) and (ii)

2x = 14 ⇒ $x = 14/2$ = 7

From equation (i)

y = 7 – 2 = 5

∴ Required product = xy = 7 × 5 = 35

Answer: (a)

84705⊗2

If sum of digit of a number is divisible by 9, then it is also divisible by 9.

⇒ 84705⊗2 = 8 + 4 + 7 + 0 + 5 + ⊗ + 2 = 26 + ⊗

Now, we replace ⊗ by 1 then it become 27 and divided by 9.

Answer: (a)

Suppose the number is x.

$x - x/7 = 180 ⇒ {7x - x}/7 = 180$

${6x}/7 = 180 ⇒ x = {180 × 7}/6$

x = 210