c语言中2.5+7%3*(int)(2.5+4.7)%2/4是如何算出等于2.5的

2.5 + 4.7 = 7.2; (int)7.2 = 7; 7 % 3 = 1; 3 * 7 = 21; //(int)7.2 = 7; 21 % 2 = 1; 1 / 4 = 0; 2.5 + 0 = 2.5;