How to find the least common multiple

Practice Questions

ISEE Upper Level (grades 9-12) Quantitative Reasoning › How to find the least common multiple

Questions

10

1

Define an operation $\bigstar$ as follows:

For all positive integers and

$a \bigstar b = \textup{lcd }(a,b) + \textup{gcf }(a,b)$ .

Evaluate $100 \bigstar 80$ .

2

Which of the following is the least common multiple of and

3

Which is the greater quantity?

(a) $50 \times 60$

(b) $LCM (50,60 ) \times GCF (50,60 )$

4

What is the least common multiple of 15 and 25?

5

Which of the following is the greater quantity?

(A) The least common multiple of 25 and 30

(B) 300

6

Which of the following is the least common multiple of 25 and 40?

7

, , , , and are five distinct prime integers. Give the least common multiple of $abc^{2}d$ and $a^{2}bde^{2}$ .

8

Which is the greater quantity?

(a) $6 \times 8 \times 10$

(b) $GCF (6,8,10) \times LCM (6,8,10)$

9

Multiply the least common multiple of 504 and 624 by the greatest common factor of 504 and 624.

10

Which is the greater quantity?

(a)

(b)

Return to subject