Straight Lines ...

If $$9@ 3 = 12, 15 @ 4 = 22, 16 @ 14 = 4$$, then what is the value of $$6 @ 2 = ?$$

Select the missing number from the given alternatives.

Directions for questions 1 to 3: Find the related word/ letters/numbers from given alternatives.
12:72::8:?

If $$12\times 16 = 188$$ and $$14\times 18 = 248$$, then find the value of $$16\times 20 = ?$$

Select the missing number from the given alternatives.

Choose the correct answer from the alternatives given.
If $$1^2+2^2$$ +.... + $$x^2$$ = $$\frac{x(x + 1)(2x + 1)}{6}$$then $$1^2$$ + $$3^2$$+ $$5^2$$ + .... + $$19^2$$ is equal to

Choose the correct answer alternatives given.
Select the missing number from the given alternatives.

If $$1^{3} + 2^{3} + .... + 10^{3} = 3025$$, then the value of $$2^{3} + 4^{3} + ..... + 20^{3}$$ is

Arrange these numbers in ascending order. 
$$756, 567, 657, 676$$