Over the last three evenings, raina received a total of 83 phone calls at the call center . the first evening, she received 7 more calls than the third evening. the second evening, she received 2 times as many calls as the third evening. how many phone calls did she receive each evening ?

X = 1st evening, y = 2nd evening, z = 3rd evening

x + y + z = 83
x = z + 7
y = 2z

z + 7 + 2z + z = 83
4z + 7 = 83
4z = 83 - 7
4z = 76
z = 76/4
z = 19 <=== 3rd evening calls

x = z + 7
x = 19 + 7
x = 26 <=== 1st evening calls

y = 2z
y = 2(19)
y = 38 <=== 2nd evening calls

She will need 5/8 bags for each square yard.