John has borrowed $6.50 from his friends and $11.75 from his sister. To find how much money he needs to repay you can just add up the amount of money he has borrowed.
Make an equation to solve for this, where x = amount of money John needs to repay. Make the amount of money John borrowed add up to x. Your equation should look like:
$6.50 + $11.75 = x
Combine like terms (add 6.50 and 11.75).
$18.25 = x
After solving the equation, you have figured out that John need to repay $18.25 in total.
Step-by-step explanation:
An arithmetic sequence is given by relation as follows :

For the first term, put n = 1. So,

For fourth term, put n = 4. So,

For tenth term, put n = 10. So,

Hence, the correct option is (C).
Median = middle number
Total ten numbers so
median = (17 + b)/2
given median = 18
so
(17 + b)/ 2 = 18
17+b = 36
b = 36 - 17
b = 19
Now you have the data set
7, a , 12, 15 , 17, 19, 20, 22, 24 , 25
Mean = (7 + a + 12+ 15 +17 + 19 + 20 + 22 +24 +25)/ 10
Given mean = 17
so
17 = (7 + a + 12+ 15 +17 + 19 + 20 + 22 +24 +25)/ 10
17 = (a + 161) / 10
a + 161 = 170
a = 170 - 161
a = 9
answer
a = 9
b = 19