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:
You can go for 1x9, 2x8, 3x7, 4x6, 5x5.
5x5 is the best as it builds a square, which maximizes space.
20*2.50 = $50.
Answer:
53
Step-by-step explanation:
c=42+11
c=53
Answer:
10
Step-by-step explanation: