Q1.
Notice the change in thickness after two folds. By how much does it increase?
Answer
It becomes 4 times as thick.
Fold 4 → 0.016 cm, Fold 6 → 0.064 cm
0.064 ÷ 0.016 = 4
Check with another pair: Fold 4 → 0.016, Fold 5 → 0.032, so one fold doubles
Two folds: 2 × 2 = 4 times
0.064 ÷ 0.016 = 4
Check with another pair: Fold 4 → 0.016, Fold 5 → 0.032, so one fold doubles
Two folds: 2 × 2 = 4 times
The book's next line asks you to check that 3 folds increase the thickness 8 times (= 2 × 2 × 2). Take fold 9 (0.512 cm) and fold 12 (4.096 cm): 4.096 ÷ 0.512 = 8. ✓
Why it happens: the factor depends only on how many folds you make, never on where you start. Each fold multiplies by 2, so k folds multiply by 2k — from fold 3 to fold 6, or from fold 30 to fold 33, the increase is the same 8 times. That is exactly what the rule 2a ÷ 2b = 2a–b is saying, and it is why the table of "times increased by" on this page reads 1024 in every row.