P + Q + R+ S + T + U + V = 900 P + S + V + T = 570.....(1) Q + S+ V + U = 424.....(2) R + V + T + U =254.....(3) Adding (1) + (2) + (3) P + Q + R+2S + 2T + 2 U + 3V = 1248 S + T + U + 2V = 348 S + T + U = 40 + 58 + 70= 168 ∵ V = 90 ∴ P + Q + R = 642 People who read all the three newspaper = 90