Find the next three terms in each of the following sequences: 1. 2, 7, 12, 17, ... 2. 87, 137, 187, 237, ... 3. 132, 128, 124, 120, ...

$7 - 2 = 5$  
$12 - 7 = 5$  
$17 - 12 = 5$

The rule is to add 5 to the previous number.  
$17 + 5 = 22$  
$22 + 5 = 27$  
$27 + 5 = 32$  
The sequence is 2, 7, 12, 17, $\boxed{\text{22}}$, $\boxed{\text{27}}$, $\boxed{\text{32}}$, ...

$137 - 87 = 50$  
$187 - 137 = 50$  
$237 - 187 = 50$

The rule is to add 50 to the previous number.  
$237 + 50 = 287$  
$287 + 50 = 337$  
$337 + 50 = 387$  
The sequence is 87, 137, 187, 237, $\boxed{\text{287}}$, $\boxed{\text{337}}$, $\boxed{\text{387}}$, ...

$128 - 132 = -4$  
$124 - 128 = -4$  
$120 - 124 = -4$

The rule is to subtract 4 from the previous number.  
$120 - 4 = 116$  
$116 - 4 = 112$  
$112 - 4 = 108$  
The sequence is 132, 128, 124, 120, $\boxed{\text{116}}$, $\boxed{\text{112}}$, $\boxed{\text{108}}$, ...

$85 - 98 = -13$  
$72 - 85 = -13$  
$59 - 72 = -13$

The rule is to subtract 13 from the previous number.  
$59 - 13 = 46$  
$46 - 13 = 33$  
$33 - 13 = 20$  
The sequence is 98, 85, 72, 59, $\boxed{\text{46}}$, $\boxed{\text{33}}$, $\boxed{\text{20}}$, ...

$\frac{14}{7} = 2$  
$\frac{28}{14} = 2$  
$\frac{56}{28} = 2$

The rule is to multiply the previous number by 2.  
$56 \times 2 = 112$  
$112 \times 2 = 224$  
$224 \times 2 = 448$  
The sequence is 7, 14, 28, 56, $\boxed{\text{112}}$, $\boxed{\text{224}}$, $\boxed{\text{448}}$, ...

$\frac{6}{2} = 3$  
$\frac{18}{6} = 3$  
$\frac{54}{18} = 3$

The rule is to multiply the previous number by 3.  
$54 \times 3 = 162$  
$162 \times 3 = 486$  
$486 \times 3 = 1458$  
The sequence is 2, 6, 18, 54, $\boxed{\text{162}}$, $\boxed{\text{486}}$, $\boxed{\text{1458}}$, ...

$\frac{12}{3} = 4$  
$\frac{48}{12} = 4$  
$\frac{192}{48} = 4$

The rule is to multiply the previous number by 4.  
$192 \times 4 = 768$  
$768 \times 4 = 3072$  
$3072 \times 4 = 12288$  
The sequence is 3, 12, 48, 192, $\boxed{\text{768}}$, $\boxed{\text{3072}}$, $\boxed{\text{12288}}$, ...

$\frac{800}{1600} = \frac{1}{2}$  
$\frac{400}{800} = \frac{1}{2}$  
$\frac{200}{400} = \frac{1}{2}$

The rule is to divide the previous number by 2.  
$\frac{200}{2} = 100$  
$\frac{100}{2} = 50$  
$\frac{50}{2} = 25$  
The sequence is 1600, 800, 400, 200, $\boxed{\text{100}}$, $\boxed{\text{50}}$, $\boxed{\text{25}}$, ...

$\frac{405}{1215} = \frac{1}{3}$  
$\frac{135}{405} = \frac{1}{3}$

The rule is to divide the previous number by 3.  
$\frac{135}{3} = 45$  
$\frac{45}{3} = 15$  
$\frac{15}{3} = 5$  
The sequence is 1215, 405, 135, $\boxed{\text{45}}$, $\boxed{\text{15}}$, $\boxed{\text{5}}$, ...

$30 - 19 = 11$  
$41 - 30 = 11$  
$52 - 41 = 11$

The rule is to add 11 to the previous number.  
$52 + 11 = 63$  
$63 + 11 = 74$  
$74 + 11 = 85$  
The sequence is 19, 30, 41, 52, $\boxed{\text{63}}$, $\boxed{\text{74}}$, $\boxed{\text{85}}$, ...