Number of keypad keys is 10, but I think you need the sum of the numbers on the keys, which is 45
Number of dog's legs, assuming no amputees or mutant dogs, is 8 x 4 = 32
Number of wheels on 3 taxis is 12, but you can add in 3 steering wheels, and/or 3 spare wheels if you want. This assumes we're talking about normal taxis, no rickshaws or motorbikes.