Answer:
18,176
Step-by-step explanation:
Figure out an easier thing to do: 1000 - 2021 = 9,797.
Therefore, our answer will be like 9999999999999999999999997979. Out of all of these digits, there are only 2 that arent nines. We know the amount of digits since it's 10^2021 power. We will have one less since we are subtracting 2021. Therefore, 2020 digits in total. Now we know of those 2020 digits, 2 of them are 7, therefore 2018 of them are 9s. That means do 2018(9) + 2(7) = 14 + 18,162 = 18,176.
Answer:
5
Step-by-step explanation:
Hello,
The two lights flash at the same time every 18 min
at 8:00 h=480 min =480+0*36
at 8:36 h=516 min =480+1*36
...
54 is not divisible by 36
60+12=72 = 2*36 yes
60+24=84 not
120+24=4*36 yes
180+18=198 not
So 2 times are correct 9:12 and 10:24
Answer G