Answer to Question 1
Electron neutrinos coming from the Sun had been detected, but in fewer numbers than predicted by theoretical models. This meant either that our models of the Sun were wrong in some way (for example, we did not correctly predict the central temperature of the Sun) or, alternatively, that we did not understand neutrinos as well as we thought we did. The solar neutrino problem was solved by the Sudbury Neutrino Observatory (SNO) in Canada which used heavy water to detect all known types of neutrinos. SNO found that the electron neutrinos emitted in the core of the Sun can change into other types as they travel through the Sun explaining why fewer electron neutrinos are detected at the Earth.
Answer to Question 2
TRUE