Tiancai Primary School held a painting and calligraphy contest with 180 students, of which only 60% participated in the painting contest, with 108 students; 10% people participated in painting and calligraphy, 18 people participated; The remaining 54 people only participated in the calligraphy competition, accounting for 30% of the participants.
180 times 0.6 to get the number of people who only participate in painting.
180 times 0. 1 to get the number of people involved in painting and calligraphy.
Then subtract 108 from 180 and then subtract 18 to get the number of people who only participate in the calligraphy competition.
Divide 54 by 180 to get 30%.