If a, b and c are positive and a^2 + c^2 = 202, what is the value of b-a-c?
(1) b^2 + c^2 = 225
(2) a^2 + b^2 = 265
(1) b^2 + c^2 = 225
(2) a^2 + b^2 = 265
Given: a^2 + c^2 = 202
A, B, C - Positive
What is the value of b - a - c?
1. b^2 + c^2 = 225
b^2-a^2 = 23
(b-a)*(b+a) = 23
You have many combinations which give you 23: 23*1, (23)^2*(1/23)
Plus you cant find out a unique value of C as well
Insuff
2. a^2 + b^2 = 265
Same problem as 1.
Combining 1 and 2
Add (b^2 + c^2 = 225) + (a^2 + b^2 = 265)
2b^2+a^2+c^2 = 490
a^2+c^2 = 202 (given)
2b^2 = 288
b^2 = 144
b = +/- 12
Since B is positive, B = 12
b^2 + c^2 = 225
c^2 = 81
c = 9
b^2-a^2 = 23
a^2 = 121
a = 11
Answer: C
