d. 40; 200; 1000; 5000 e. 6; 36; 216; 1296 f. 3; 9; 27; 81; 243 g. 5; 20; 80; 320; 1280 h. 7; 42; 252; 1512 i. 9; 45; 225; 1125 j. 10; 20; 40; 80; 160

$$\frac{40}{8} = 5$$ $$\frac{200}{40} = 5$$

The common ratio is 5.

$$5000 \times 5 = 25000$$

The next term is $\boxed{\text{25000}}$.

$$\frac{6}{1} = 6$$ $$\frac{36}{6} = 6$$

The common ratio is 6.

$$1296 \times 6 = 7776$$

The next term is $\boxed{\text{7776}}$.

$$\frac{9}{3} = 3$$ $$\frac{27}{9} = 3$$

The common ratio is 3.

$$243 \times 3 = 729$$

The next term is $\boxed{\text{729}}$.

$$\frac{20}{5} = 4$$ $$\frac{80}{20} = 4$$

The common ratio is 4.

$$1280 \times 4 = 5120$$

The next term is $\boxed{\text{5120}}$.

$$\frac{42}{7} = 6$$ $$\frac{252}{42} = 6$$

The common ratio is 6.

$$1512 \times 6 = 9072$$

The next term is $\boxed{\text{9072}}$.

$$\frac{45}{9} = 5$$ $$\frac{225}{45} = 5$$

The common ratio is 5.

$$1125 \times 5 = 5625$$

The next term is $\boxed{\text{5625}}$.

j)

$$\frac{20}{10} = 2$$ $$\frac{40}{20} = 2$$

The common ratio is 2.

$$160 \times 2 = 320$$

The next term is $\boxed{\text{320}}$.