29. When from the numbers from 1 to 333 Tanya excluded all numbers divisible by 3 but not divisible by 7, and all numbers divisible by 7 but not divisible by 3, she ended up with 215 numbers. Did she solve the problem correctly?
29. There are 333 numbers in total, of which 111 numbers are divisible by 3 ( $333: 3=111$ ); among these numbers, 15 are divisible by 7 ( $333:(3 \cdot 7)=333: 21=15$ (remainder 18)). Therefore, the numbers divisible by 3 but not by 7 total 96 numbers ( $111-15=96$ ). There are 47 numbers in total that are divisible by 7 ( $333: 7=47$ (remainder 4)). Among these 47 numbers, 15 are divisible by 3, so the numbers divisible by 7 but not by 3 total 32 numbers ( $47-15=32$ ). Thus, 128 numbers need to be crossed out (excluded) ( $96+32=128$ ), leaving $333-128=205$ numbers. By obtaining 215 numbers, Tanya made a mistake.