Norma takes her clothes to the laundry. She leaves 9 T-shirts and twice as many sweaters as T-shirts in the washer. When she returns she finds 3 sweaters and triple the number of T-shirts. How many items are missing? Let's answer step by step:
Norma left 9 T - shirts And twice as many sweaters, she took 9 * 2 = 18 sweaters. Adding the T - shirts and sweaters, Norma left 9 + 18 = 27 clothes. When she came back, she found 3 sweaters And triple the number of T - shirts, she found 3 * 3 = 9 T - shirts. Adding the T - shirts and sweaters, Norma found 3 + 9 = 12 clothes. Subtracting the clothes she left from the clothes she found, 27 - 12 = 15 clothes are missing. The answer: 15.