Question

A house of cards or card castle is a structure created by stacking playing cards on top
often in shape of pyramid. To build a tower of cards 2 cards are placed against each oth
down position forming a triangular shape. Another triangle next to it and so on. S
repeated in next row and so on. A man formed such a house of cards with 41 such tria
base, 39 in the next, 37 in next and so on. He made 16 such rows in this ma
another
Number of triangles in the top row is
(a) 10
(b) 11
(c) 12
(d) 9​

Answer 1

The correct answer is (b) 11.

The problem describes a card castle that was built by stacking playing cards on top of each other in the shape of a pyramid. The number of triangles in each row decreases by 2 as we move up from the base. The base has 41 triangles, so the second row has 39, the third row has 37, and so on. There are a total of 16 rows. To find the number of triangles in the top row, we can use the formula:

Number of triangles in top row = Number of triangles in base row - 2 * (Number of rows - 1)

Plugging in the given values, we get:

• Number of triangles in top row = 41 - 2 * (16 - 1)
• Number of triangles in top row = 41 - 2 * 15
• Number of triangles in top row = 41 - 30
• Number of triangles in top row = 11

Therefore, the correct answer is (b) 11. The formula used to find the number of triangles in the top row is a general formula that can be used for any pyramid shape where the number of triangles in each row decreases by a constant amount.

For more questions on Mathematics

https://brainly.in/question/1102376

#SPJ3