How many read only The Hindu?

Total Clients: 170

Clients who read Indian Express: 115;

Clients who read The Hindu: 110;

Clients who read Times of India: 130;

Clients who read two common papers:

1) Indian Express + Times of India = 85;

2) Indian Express + The Hindu = 75;

3) The Hindu + Times of India = 95;

Clients who read all three papers = 70

1) Clients who read only Indian Express and Times of India = 85 - 70 = 15

2) Clients who read only Indian Express and The Hindu = 75 - 70 = 5

3) Clients who read only The Hindu and Times of India = 95 - 70 = 25

Now,

The clients who read only Indian Express = 115 - (5 + 70 + 15) = 25

The clients who read only The Hindu = 110 - (5 + 70 + 25) = 10

The clients who read only Times of India = 130 - (15 + 70 + 25) = 20

Hence, 10 clients read only The Hindu.