1. There are six red balls and six yellow balls in the box. How many balls can guarantee two different colors? (10)

6+ 1=7 (pieces)

2. How many minutes does it take a cat to eat one fish and five fish of the same size? (10)

5×5=25 (minutes)

Miss Wang has a daughter, and so does Miss Li. How many daughters do two teachers have? (10)

There are 1 daughters, because they are a family.

4. Xiaogang lit 20 candles, first 7 were blown out by the wind, then 9 were blown out by the wind, and Xiaogang himself blew out 1. The next morning, Xiao Gang found how many candles were left. (10)

7+9+ 1= 17 (branch)

5. 15 Tennis balls are divided into four piles with different numbers. How many balls are there in the largest pile? (10)

The first pile: 2; The second pile: 3.

The third pile: 4. The fourth pile: 6.

There are at least six tennis balls in the most pile.

6. Sweet children arrange 30 beads in five piles, with different numbers. The number of beads in each pile is exactly even. Do you know how many there are in each pile? (10)

The first pile: 2; The second pile: 4.

The third pile: 6; The fourth pile: 8; The fifth pile: 10.