There are 720 students in Ruizhi School, and the number of students transferred at the beginning of this semester is equivalent to 1/20 of the original number of boys. At this time, the school has more 18 students than before. How many boys are there in this school?

18 1/20 = 360 (person)

There used to be 360 boys in this school.

There are two packets of sugar. The first packet contains 30 pieces. If you take 1/5 from the second package and put it in the first package, the second package is 3 more than the first package. How many sweets are there in the second package?

There are x pieces of sugar in bag B.

30+ 1/5X+3 =( 1- 1/5)X

33+ 1/5X=4/5X

3 5X = 33

X=55

There are 55 pieces of sugar in bag B.