In a triangle with sides a=10a = 10a=10, b=12b = 12b=12, c=15c = 15c=15, find cos(C)\cos(C)cos(C).
1940\frac{19}{40}4019
−724-\frac{7}{24}−247
2425\frac{24}{25}2524
724\frac{7}{24}247