basic numeracy Model Questions & Answers, Practice Test for ssc cgl tier 1

Answer: (a)

Let the hundreds digit be n.

The tens digit will be 2n.

The unit digit will be 4n.

The possible values of 'n' are 1 and 2 and hence the possible numbers are 124 and 248 respectively.

On converting 248 in base 8 and base 9, the given condition gets violated.

On converting 124 in base 8 and base 9, we get $(174)_8 = (147)_9$.

Required sum = 4 + 7 = 11.

Answer: (b)

Option C is incorrect as 6n – 1 form can be a prime number but it is not necessarily true.

Answer: (e)

Let the cost of one chair be Rs. x and that of a table be = Rs.y

According to the question,

3x + 10y = Rs.9856

or, 2 × (3x + 10y) = 2 × 9856

∴ 6x + 20y = Rs.19712

Answer: (c)

Original number = h × 100 + t × 10 + u

Number obtained by reversing digits

= u × 100 + t × 10 + h

∴ Required number = (h × 100 + t × 10 + u)

– (u × 100 + t × 10 + h) = 99 (h – u)

But the unit's place digit in above number is 4, therefore (h – u) should be 6, then number is 594.

Whose digits are 5, 9, 4 respectively.

Answer: (c)

Let the number be (10x + y)

Then, (10x + y) – (10y + x) = 18

9x – 9y = 18

x – y = 2 ...(i)

and, x + y = 16 ...(ii)

x = 9, y = 7

From equations (i) and (ii),

So, the number is (10 × 9 + 7) = 97