1)* * * The original score is 7+2=9, and each score is 36/9 = 4 balls; There was a yellow ball. 4*2=8.

Now there are 2 1+4=25 yellow balls, 4 yellow balls and 8 yellow balls, so there are 2 yellow balls each, and now there are 2*25=50 yellow balls.

2) The number of times done per hour = the total number of times: the time done now is the same, so the ratio of times done is equal to the ratio of times done per hour; A does 60 per hour and B does 45 per hour.

That is, the number of products manufactured by B: 240=45: 60=3:4, so B manufactured 180 products.

B is 240- 180=60 less than A.

3) At present, there are 2.7/2kg large bottle oil and 2.7 kg small bottle oil.

Now the oil in a large bottle is the original (1- 1/4)=3/4, so the original oil in a large bottle is 2.7/2/(3/4) =1.8kg..

Original vial oil 2.7- 1.8=0.9kg.

4) Suppose the calligraphy group 1, the art group 2/3 and the sports group 5/4.

Then there is the calligraphy group: art group: sports group =1:2/3: 5/4 =12: 8:15.

That is, there are 12+8+ 15=35 copies in total, so each copy is 140/35=4 people.

So there are 12*4=48 people in the calligraphy group, 8*4=32 people in the art group and 15*4=60 people in the sports group.

5) 8 players and 4 games in the first round; In the second round, two games for four people; In the third round, two players have 1 game, so there are 4+2+ 1=7 games.