Bunuel wrote:

Sofi has S game cards, which is half as many as her older brother has, and three times as many as her younger sister has. In terms of S, how many game cards do the three siblings have altogether?

A. 4S/3

B. 7S/3

C. 10S/3

D. 7S/2

E. 11S/2

Let S = 6, older brother = 12, younger sister = 2

Total cards =20

A. 4S/3 = 4 * 6/3 = 8.............Eliminate

B. 7S/3 = 7 * 6/3.......Not multiple of 10 as in my answer.....Eliminate

C. 10S/3 = 10 * 6/3 = 20................Keep

D. 7S/2.............Same as B

E. 11S/2.............Same as B

Answer: C