Which[# < .4, b, # < .7, c, True, #] & /@ t
Table[Which[# < .4, b, # < .7, c, True, #] &[t[[i]]], {i, 1, Length[t]}]
beautifully done, thank you Jaeyong Sung
`
Table[Which[# < .4, b, # < .7, c, True, #] &[t[[i]]], {i, 1, Length[t]}]`