Answer:
12.
Step-by-step explanation:
To find the mean of a group of data, you add up all of the numbers and divide the total by the amount of numbers there are. In this case, you have 15,11,10,11,14,10,15,10,and 12.
All of those numbers added together is 108.
108 divided by 9 numbers, or weeks, is 12.
The average, or mean, is 12.
1/52, as there is only 1 ace of hearts in a standard deck (no jokers) of 52 cards.
.33 x 48
15.84
48 - 15.84
$32.16
---------------
125 x 1.08
$135
Answer:
They are the came length. And are like mirrored.
Step-by-step explanation:
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.
