Answer:
All your steps are correct. Well done!
2 x 10000 = 20000
2 x 10 x 10 x 10 x 10
The answer is 2 x 10^4
The first digit of a number can be 1-9. The 2nd and the 3rd digit can be 1-10. The last digit can be 0 or 5 ( 2 numbers ):
9 * 10 * 10 * 2 = 1,800
She could pick 1,800 different 4-digit numbers.
Da answer is 21,000 Pounds Couse 9 + 10 = 21
