The average of marks obtained by X and Y is 35 less than the average marks obtained by Y and Z. If the marks obtained by Z is 85, what is the marks obtained by X ?

155 15 35 25

15

Lets assume avg. marks obtained by Y and Z is a, so avg. marks obtained by X and Y are a - 35 As marks obtained by Z = 85, ⇒ marks obtained by Y = 2a - 85 As per question, X + Y = 2 x (a - 35) X + 2a - 85 = 2a - 70 X = 15