Final answer:
By dividing the total cost of $117.50 by the number of flash drives, which is 18, we get approximately $6.53 per flash drive. Given the estimate options provided, the closest and best estimate for the cost of each flash drive is $6.
Step-by-step explanation:
To estimate the cost of each flash drive, you can divide the total cost Tiyana paid by the number of flash drives she bought. Tiyana paid $117.50 for 18 identical flash drives. To find the cost per flash drive, you divide $117.50 by 18.
Doing the division, you get approximately $6.53 per flash drive. However, you're asked for the best estimate, and given the choices (A) $6, (B) $10, (C) $12, and (D) $60; the closest estimate to $6.53 is $6.
Therefore, the best estimate for the cost of each flash drive is $6, which corresponds to option (A).