Two mixers and one T.V. cost Rs. 7000, while two T.V.s and a mixer cost Rs, 9800. The value of one T.V. is:  Choose the correct choice:
A) rs . 4000 B) rs . 4500 C) rs . 4300 D) rs . 4200 E) none of these

Rationale: explanation : let c . p . of a mixer be rs . x and that of a t . v . be rs . y . then , 2 x + y = 7000 and 2 y + x = 9800 . multiplying 2 nd equatien by 2 and subtracting first from it , we get 3 y = 19600 - 7000 = 12600 or y = 4200 c . p . of a t . v . = rs . 4200 answer : d
Answer: D