GRE Prep Club Team Member
Joined: 20 Feb 2017
Posts: 2508
Given Kudos: 1053
GPA: 3.39
Re: If the average of a, b, c is 120 and average of a, b, d is 60. Then wh
[#permalink]
27 Jul 2023, 11:58
To find the value of (d - c), we first need to find the values of a, b, c, and d.
Let's assume a, b, and c are the common elements in both sets (averages of a, b, c, and a, b, d). The average of a, b, c is given as 120, so we can write:
(a + b + c) / 3 = 120
Similarly, the average of a, b, d is given as 60:
(a + b + d) / 3 = 60
Now, we can solve these two equations to find the values of a, b, c, and d.
(a + b + c) = 120 * 3
a + b + c = 360
(a + b + d) = 60 * 3
a + b + d = 180
Now, subtract equation 1 from equation 2:
(a + b + d) - (a + b + c) = 180 - 360
d - c = -180
So, the value of (d - c) is -180.
Therefore, the correct answer is:
B. – 180