If a and b are two odd positive integers, by which of the following integers is (a⁴ - b⁴) always divisible?

• 3

• 6

• 8

• 12

If x * y = (x + 3)2  (y - 1), then the value of 5 * 4 is

• 192

• 182

• 180

• 172

 is

• 10

• 100

• 1000

• None of these

If X * Y = X² + Y² - XY,  then  11 * 13 is

• 117

• 147

• 290

• 433

If a and b are odd numbers, then which of the following is even?

• a + b + ab

• a + b - 1

• a + b + 1

• a + b + 2ab

If a^1/3 = 11,  then the value of a² - 331 a is

• 1331331

• 1331000

• 1334331

• 1330030

207.

If  then the value of  is

• 

• 

• 

• 

If  then the value of  is

If  then the value of  is

If a² + b²  + c² = 2 (a - b - c) - 3,  then the value of 2a - 3b + 4c is

• 3

• 1

• 2

• 4