# Joint PDF. Is my book wrong?

Consider that X and Y have the joint pdf $f(x,y) = (2/3)(x+1)$ for $0 < x < 1$ and $0 < y < 1$ and 0 otherwise. What is $P(X < 2Y < 3X)$? My book say the answer is 73/162

But I keep doing $\int_0^1 \int_{x/2}^{3x/2} f(x,y) \, dy \, dx$ and I am not getting 73/162

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