Gertrude has 10 fleas and Olive has half that amount so Olive has 10/2 = <<10/2=5>>5 fleas
Maud has 5 times the amount of fleas as Olive who has 5 fleas so Maud has 5*5 = <<5*5=25>>25 fleas
Gertrude has 10 fleas, Maud has 25 fleas and Olive has 5 for a total of 10+25+5 = <<10+25+5=40>>40 fleas
#### 40