It’s C. I have to put more letters just ignore this
<em>Greetings from Brasil...</em>
The average for a set of 9 elements will be
(A + B + C + D + E + F + G + H + I) ÷ 9 = 20
Let's make (A + B + C + D + E + F + G + H + I) like S
<em>(I chose S to remember a sum)</em>
Let us think.....
S ÷ 9 = 20
S = 20 × 9
S = 180
So, (A + B + C + D + E + F + G + H + I) = 180
According to the statement, we will include a number (element J) in the sum to obtain a mean of (20 - 4), that is:
<h3>(A + B + C + D + E + F + G + H + I +
J) ÷ 10 = (20 - 4)</h3>
as seen above, (A + B + C + D + E + F + G + H + I) = 180, then
(180 + J) ÷ 10 = 16
(180 + J) = 160
J = 160 - 180
<h2>J = - 20</h2><h2 />
So, including the number - 20 <em>(minus 20)</em> in the original mean we will obtain a new mean whose result will be 16
This is I suppose basic addition. Addition is a mathematical process of combining or joining something to something else. The word "total" indicates that the addition will be used. If the doctor ran for 55 hours and the mom for 52 hours, by using the addition it will be:
55
+ 52
______
107 hours in total.
107 hours converted in days will be 4 days and 4 hours. SInce 1 day contains 24 hours you now divide 107 hours by 24 hours to get its equivalent to days.
