Question $1\mathrm{.}30$ please

$1\mathrm{.}30$ Two wooden members of uniform rectangular cross section are joined by the simple glued scarf splice shown. Knowing that the maximum allowable shearing stress in the glued splice is $620$ kPa $,$ determine $($a$)$ the largest load $P$ that can be safely applied, $($b$)$ the corresponding tensile stress in the splice.