There is no question here
A) The first step needs 100 bricks, the second needs 98, the third needs 96, and so on. Therefore the number of bricks for the nth step is: a_n = a_1 + d(n-1), where a_1 = 100 (the first term), d = -2 (difference).
a_n = 100 - 2(n-1) = 102 - 2n, and for the 30th step, a_30 = 102 - 2*30 = 42. So the top step will need 42 bricks.
b) The total staircase will need: 100 + 98 + 96 + ... + 44 + 42, and there are n = 30 terms. Using the formula for the sum of an arithmetic sequence:
S = (a_1 + a_n)*n/2 = (100 + 42)*30/2 = 2130
Therefore, 2130 bricks are required to build the entire staircase.
Answer:
squares
Step-by-step explanation:
Answer:
$30.72
Step-by-step explanation:
You were right with your answer, the teacher is probably just wanting you to tip on the subtotal (before tax) instead of the total total. Instead of doing total+tax+tip, we're going to figure out the tax and tip separately and then add it all together.
<u>Tipping on the subtotal (what your teacher wanted)</u>
20% of $24 = $4.80
8% of $24 = $1.92
$24+$4.80+$1.92=$30.72
<u>Tipping on the total (what you did)</u>
8% of $24 is $1.92
New total is $25.92
20% of $25.92 is $5.18
$25.92 + $5.18 = $31.10
