Power of a Quotient Rule for Exponents: Number of terms

Simplify the following:

$\frac{b^{10}}{b^2}:\frac{b^9}{b^5}=$

$b^4$

Simplify the following:

$\lbrack\frac{a^4}{a^3}\times\frac{a^8}{a^7}\rbrack:\frac{a^{10}}{a^8}$

$1$

Simplify the following:

$\frac{a^{12}}{a^9}\times\frac{a^3}{a^4}=$

$a^2$

Solve the following:

$\frac{y^3}{y^6}\times\frac{y^4}{y^{-2}}\times\frac{y^{12}}{y^7}=$

$y^8$