A pattern for the number of cups for figure n is Cn = 2n − 1. Verify the number of cups for the 15th and 20th figures.

This is the same problem we discussed previously. Let's verify the answers you've written on the paper.

a) What will be the number of cups for the 15th figure?
Your answer: 29
The pattern for the number of cups (C) for figure (n) is $C_n = 2n - 1$.
For the 15th figure:

$$C_{15} = 2(15) - 1 = 30 - 1 = 29$$

✅ Correct. The number of cups for the 15th figure is 29.

b) What will be the number of cups for the 20th figure?
Your answer: 61
Using the same pattern $C_n = 2n - 1$:
For the 20th figure:

$$C_{20} = 2(20) - 1 = 40 - 1 = 39$$

❌ Incorrect. The number of cups for the 20th figure is 39, not 61.