number system Model Questions & Answers, Practice Test for ssc chsl tier 1 2024

Answer: (d)

Let numbers be a, b and c respectively

According to the question

a × b = 286

b × c = 770

Value of b is H.C.F of 286 and 770 = 22

∴ a = 13; b = 22; c = 35

a + b + c = 13 + 22 + 35 = 70

Answer: (d)

It is always correct that the product of two square numbers is a square number.

e.g., 4 × 9 = 36

Answer: (d)

$√{x/y} = 10/3 - √{y/x}$

$√{x/y} = 10/3 - 1/√{y/x}$

Let $√{x/y} = z$

∴ z = $10/3 - 1/z ⇒ 3z^2 - 10z + 3 = 0$

⇒ z = 3 or $1/3$

⇒ $√{x/y} = 3$ or $√{x/y} = 1/3$

⇒ x = 9y ...(i)

or 9x = y ...(ii)

But x – y = 8 ...(iii)

∴ x > y

Hence eq. (ii) is rejected

From eq. (i) and (iii),

9y – y = 8, ⇒ y = 1 and x = 9

∴ xy = 9 ´ 1 = 9

Answer: (d)

311 is repeated seven times in the number, 311 is not divisible by 3 but 311 repeated twice is not divisible by 3, but divisible by 11.

Similarly 311 repeated thrice is divisible by 3, but not by 11.

As 311 is repeated seven times, which is neither multiple of 2 nor 3.

So, number is not divisible by 3 or 11.

Answer: (a)

Time taken to reach 5'O Clock = 8 seconds

Time taken to reach 10'O Clock = $8/5$ seconds

Time taken to reach 10'O Clock

= $8/5 × 10$ =16 seconds

∴ Option (b) is correct.