The lines $x+2 \mathrm{a} y+\mathrm{a}=0, x+3 \mathrm{~b} y+\mathrm{b}=0$, $x+4 c y+c=0$ are concurrent then $a, b, c$ are in

In a box containing 100 apples, 10 are defective. The probability that in a sample of 6 apples, 3 are defective is

The value of the integral $\int_1^2 \frac{x \mathrm{~d} x}{(x+2)(x+3)}$ is

The general solution of the differential equation $\frac{\mathrm{d} y}{\mathrm{~d} x}+\sin \left(\frac{x+y}{2}\right)=\sin \left(\frac{x-y}{2}\right)$ is