Redox question help, final oxidation state

if u look at the equation they’ve given u, in order for the dichromate ions to become reduced to chromium3+ ions, u need 6 electrons. the reacting ratio of dichromate ions to manganese2+ ions is 1:3 so if 1 mole or dichromate ions gain 6 electrons, this is because 3 moles of manganese2+ ions lose the 6 electrons. that means 1 mole of manganese2+ loses 2 electrons each. this changes the oxidation of manganese ions from 2+ to 4+.