AAI ATC Junior Executive 2016 Shift 2 Paper

X-rays of wavelength of 0.0650 nm undergo Compton scattering from free electrons in a target. What is the wavelength of photons scattered at 90° relative to the incident rays? (h = 6.63 × 10^-34 J s, m_e = 9.11 × 10^-31 kg, c = 3 × 10⁸ m/s)