Two long, straight wires carry equal currents in opposite...

The direction of the magnetic field at the observation point due to the current carrying conductor is determined by the right-hand cork screw rule.

From the given diagram, it is clear that as the conductors carry current in the mutually opposite direction, the direction of the magnetic fields produced by them at point $P$ will be the same.

Hence, the required magnetic field at $P$ due to the conductors can be calculated as follows:

$\begin{cases}B & = & 2 \times \left(\dfrac{{\mu}_{0}i}{2\pia}\right) \\ & = & 2 \times \dfrac{4\pi \times {10}^{- 7} \times 10}{2\pi \times \left(\dfrac{5}{2} \times {10}^{- 2}\right)}T \\ & = & 160 \times {10}^{- 6}T \\ & = & 160\mu T\end{cases}$