Answer:
C?
Step-by-step explanation:
Joel = j, Mark = m, Sandra = s
j + m + s = 120
m = 3j
j = 1/2 s --> s = 2j
plug in (substitute) each letter to make it in terms of only j: j + m + s = 120
j + 3j + 2j = 120
6j = 120
6j/6 = 120/6
j = 20
now plug in for the j & s equation:
s = 2j = 2(20) = 40
Therefore Sandra has 40 coins!
can u plz take a more clearer photo of the problem and also try to elaborate
Answer:

Step-by-step explanation:
a.


See attached diagram.
b.

Answer:
Yes
Step-by-step explanation:
8 73/
100=8.73