(2) Yes.

(3) It is possible to weigh it out at one time. Because if you put four baskets at each end of the balance, the balance is just balanced, and the remaining baskets are eaten by the little squirrel, then you can find out the basket of pine cones that the little squirrel has only eaten once; If it is unbalanced, it will take two or three times to weigh it out, so this method is the best.

2.

Divide the 15 box into three powders evenly, and weigh it at least three times to ensure that you can find the lighter box of biscuits.

3.

7+4/5=43/35 5/ 12+5/8=25/24 7/9+7/6= 103/63 1-2/7-3/7=2/7

1/4+ 1/6+3/4=7/6 1/2- 1/6= 1/3

4.

Analysis: The age difference between Dad and Xiaoming is the same, and it is the same now and three years later.

Answer: Suppose Xiaoming is X years old, then his father is (X+24) years old.

X+24+x=34

X=5

So Xiao Ming is 5 years old and his father is 5+24=29 (years old).