TeX source:

v^{\prime}=\left(\frac{0.150 \mathrm{~kg}}{0.150 \mathrm{~kg}+70.0 \mathrm{~kg}}\right)(35.0 \mathrm{~m} / \mathrm{s})=7.48 \times 10^{-2} \mathrm{~m} / \mathrm{s}