lcm and hcf Model Questions & Answers, Practice Test for ibps rrb clerk asst multipurpose prelims 2024

Answer: (d)

Here given the HCF of 144, x, 192 is 12.

x can not be 48 because HCF is 12.

Answer: (b)

Let the numbers be 24x and 24y.

∴ 24x × 24y = 6912⇒xy = ${6912}/{(24)^2}$ = 12

∴ LCM is 24 × 12 = 288

Answer: (d)

Let 2 natural numbers m and n are 12 are 18.

∴ HCF of 12 and 18 = $g_{mn}$ = 6

Let third natural number k is 20.

So, $g_{nk} = HCF (18, 20) = 2 and g_{mk}$ = 4

So, $g_{m(nk)}$ = HCF (12, 360) = 12

So, $g_{(mn)k}$ = HCF (216, 20) = 4

From I statement, $g_{m(nk) ≠ g_{(mn)k}$

From II statement, $g_{mn} g_{nk} ≠ g_{mk}$

So, both statements are false.

Answer: (b)

Product of numbers = HCF × LCM

⇒ The other number =$ {4800× 160}/480=1600$

Answer: (c)

$3√{4 {12}/{125}} = 3√{{512}/{125}} = 8/5 = 1{3/5}$