For a flat (k=0) universe with no cosmological constant, consider a relation between the age of the Universe and the "Hubble Time", tH = 1/ Ho. Answer the questions below in the box provided. Make sure you enter your answer so it is clear what is part (A), (B), and (C) so the grader can read them. A. [6 points] Show that to = C-. where to is the present-day age of the Univese and calculate the value of "O". Hint: consult the discussion in section 29.1 of the textbook and remember that Ro = 1 at present ("now"). B. [2 points] The value of Hubble's Constant is a subject of ongoing research. A recent value measured locally (the same way Edwin Hubble did it) is from Riess et al. (2016, ApJ, 826, 56), who find Ho = 73.24 + 1.74 km/s/Mpc. What is the value of to in this case? Give your answer in Gyr. C. [2 points] The value from Riess et al. is in tension with the value measured from CMB data by the Planck mission (Planck Collaboration 2018, https://arxiv.org/abs/1807.06209), Ho = 67.4 + 0.5 km/s/Mpc. What is the value of to in this case? Give your answer in Gyr