Using the expression 2n - 1 can you find out how many tiles will be there in the 15th stage Class 9

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· Jul 03, 2026 · Reviewed & updated Sep 17, 2026 · 1 min read

Using the expression 2n - 1 can you find out how many tiles will be there in the 15th stage Class 9

Question 1.

Using the expression 2n - 1, can you find out how many tiles will be there in the 15th stage and the 26th stage of the pattern? Also, which stage will contain 21 tiles and 47 tiles? Class 9

Answer:

Number of tiles at stage n = 2n - 1

Substituting n = 15 in 2n - 1, we get

2(15) - 1 = 30 - 1 = 29

∴ There will be 29 tiles in the 15th stage.

Substituting n = 26 in 2n - 1, we get

2(26) - 1= 52 - 1 = 51

∴ There will be 51 tiles in the 26th stage.

For 21 tiles,

2n - 1 = 21

∴ 2n = 21 + 1= 22

∴ n = [latex]\frac{22}{2}[/latex]

∴ n = 11

∴ The 11th stage will contain 21 tiles.

For 47 tiles,

2n - 1 = 47

∴ 2n = 47 + 1= 48

∴ n = [latex]\frac{48}{2}[/latex] = 24

∴ The 24th stage will contain 47 tiles.