Number Theory
# Greatest Common Divisor / Lowest Common Multiple

What is the common divisor of \( 33 \) and \( 55 \) except \(1\)?

Simplify\[\dfrac{2^2 \times 3}{2 \times 3 \times 5} .\]

What is the greatest common divisor of 35 and 91?

What is the gcd(A, B) if:

A = \( 6 \times 35, \) and

B = \( 8 \times 15? \)

Simplify \[\dfrac{15}{20}. \]

**Details and assumptions:**

- You may use the fact that \( 15= 3 \times 5\) and \( 20 = 4 \times 5\).