Step-by-step explanation:
Initially, there's only 1 letter.
Tania sends the letter to 4 friends.
Each friend sends a letter to 4 more friends (4 × 4 = 16).
Each of those friends sends to 4 more friends (16 × 4 = 64).
The pattern is 1, 4, 16, 64, etc.
This is a geometric sequence. The first term is 1 and each term is 4 times the previous term.
a₁ = 1
aₙ = 4 aₙ₋₁
The explicit formula is:
aₙ = 1 (4)ⁿ⁻¹
176 feet per sec × 6o secs in a minute = 10560
Answer:
A, B and D
Step-by-step explanation:
Given:
A prism with height 5 cm and equilateral triangular base with side 2 cm.
To find:
The total surface area of the prism.
Solution:
Area of an equilateral triangle is:

Where, a is the side length.
Putting
, we get




The base and top of the prism are congruent so their area must be equal.
The lateral surface area of the prism is:

Where, P is the perimeter of the base and h is the height of the prism.
The lateral surface area of the prism is:



Now, the total surface area is the sum of areas of bases and lateral surface area.




Therefore, the total surface area is 33.46 cm².