2. X is the number of large vehicles, and Y is the number of small vehicles X+Y=9 40X+ 10Y=240 X=5 Y=4.
3. Because the final subtraction of 25 is equal to 0, the final subtraction of 25-25, subtraction of 26 25, and addition of 25 22.
4.a, B, C and D should be 3.5.11.193+5+1=193× 5×1
5. The number 1 appears 50 times (1,1,2 1, 3 1, 4 1, 5 1, 6/kloc).
Numbers with 1 in the ten digits appear 50 times (10,1,12, 13, 14, 15,/.
The number with 1 in the hundreds appears 100 times (100,10, 103, 104... 199.
50+50+ 100=200 (piece)