I don’t think you have to worry about it because you
I think 20×5=100 then 100÷2
10.5 in the form of a/b = 105/10 = 21/2
If by standard from you mean numbers (123) and not words then
1 milllion=1000 thousand or 1000*1000 or 1,000,000
1 billion=1000 million=1000*1000*1000=1,000,000,000
so 7billion=7*1000*1000*1000=7,000,000,000
I think the answer is 21. I’m not sure but if I remember it’s 40 + 20 = 60. 180 - 60 = 120 and then it’s a vertical angle which is equal so then it would be 120 + 39 = 159. Then 180 - 159 = 21. Sorry if this is wrong I haven’t done this in a while. Have a good day!
