If Fred has 12 identical candy bars, uncle Bob has 12+6=<<12+6=18>>18 candy bars.
Together, Fred and Uncle Bob have 12+18 = <<12+18=30>>30 candy bars.
Jacqueline has ten times the total number of candy bars Fred and Uncle Bob have, meaning she has 10*30 = <<10*30=300>>300 candy bars.
40% of Jacqueline's candy bars is 40/100*300 = <<40/100*300=120>>120
#### 120