Question

Kaushal saw following mage of tennis balls stacked jn a tetrahedron pack on an e - commerce Site and ordered
the stack of balls. He thought that his packet has 15 balls. He jumped out of joy as he found that number of balls in
the packet are more than his expectation.


Please tell the answer fast

Answer 1

Given : Kaushal saw following mage of tennis balls stacked jn a tetrahedron pack on an e - commerce Site and ordered

the stack of balls. He thought that his packet has 15 balls. He jumped out of joy as he found that number of balls in

the packet are more than his expectation.

To Find : number of balls

Solution:

Balls in  top layer = 1

Balls in  2nd layer from top = 1 + 2 = 3

Balls in  3rd  layer from top = 1 + 2 + 3 = 6

Balls in  4th  layer from top = 1 + 2 + 3 + 4 = 10

Balls in  5th  layer from top = 1 + 2 + 3 + 4 + 5 = 15

Total Balls = 1 + 3 + 6 + 10 + 15   = 35

35 - 15 = 20

20 more ball in packet than expected

for k layers it can be written as  $\sum_{n=1}^k \frac{n(n+1)}{2}$

Learn More:

what is tetrahedron

brainly.in/question/303538

Find the volume of the tetrahedron

brainly.in/question/6962830