Answer: you can
Step-by-step explanation:

1) Since in the USA 8 x 10 ^9 messages are sent every month, that means that approximately 8 billion messages are sent.
2) We can Prime factorize it:
Note that on the right side we've picked only prime numbers. In this case, 2 and 5.
So we can rewrite 8 x 10^9 as prime factors.

3) Hence, the answer is:
Answer:
1.5
Step-by-step explanation:
a+8=b+5
a+3=b
b=1.5
Answer:
Step-by-step explanation:
You can split the coins into 3 groups, each of them has 3 coins. Weigh group 1 vs group 2, if one is lighter, that group has the fake coin. If both groups weigh the same, then group 3 has the fake coin.
Continue to split the group that has the fake coin into 3 groups, each group has 1 coin. Now apply the same procedure and we can identify the fake coin.
Total of scale usage is 2
b) if you have
coins then you can apply the same approach and find the fake coin with just n steps. By splitting up to 3 groups each step, after each step you should be able to narrow down your suspected coin by 3 times.
Step 1: you narrow down to group of
coins
Step 2: you narrow down to group of
coins
Step 3: you narrow down to group of
coins
...
Step n: Step 1: you narrow down to group of
coin
Answer:
21
Step-by-step explanation:
You do the parentheses first, so 27/9 = 3
10-3 = 7
3 * 7 = 21