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

Answer: (b)

They will be together at the starting point after the L.C.M of 36, 48 and 42

L.C.M. of 36, 48, 42 = 1008 seconds

Answer: (b)

Term divisible by 15 are 15, 30, ... 300

Let n be the total terms 300 = 15 + (n - 1) × 15

n = $300/15 = 20$

Answer: (b)

161, 171, 221, are divisible by 7, 3 and 13 respectively.

But 173 is not divisible by any others numbers except 1 and 173.

Answer: (a)

From the given alternatives,

112 × 114 = 12768

∴Larger number = 114

While attempting these types of questions, it is always advisable to multiply the number at unit's place to see if we are getting the same number in unit's place as given in the question.

Now 1st option is 110, previous consecutive even number will be 108, 0 × 8 = 0, but the number given in the question has 8 at unit's digit, therefore 'a' cannot be the correct option, so, there is no need to waste your time over it.

Answer: (b)

I. It is true that every integer is a rational number.

e.g., Set of integers,

Z = {..., ${- 3}/1, {- 2}/1, {- 1}/1, 0/1, 1/1, 2/1, 3/1$ , ...}

which of the form $p/q$, which also shown rational numbers.

II. It is also true that every rational number is a real number because a real number does not contain i (iota).

So, both statements are true.