Math

posted by Beth

Bill is saving money in an empty jar. The first day he puts in a certain amount of money. Every day after the first he puts in 2 more dollars than the amount he put in on the previous day. After 10 days he has put 200 dollars in the jar. How much money did he pit in the jar on the first day?
Is there a more concise way of doing this than writing x+x+2+x+4+x+6.... Etc until 10?

  1. Steve

    use what you know about arithmetic progressions.

    10/2 (2a+9*2) = 200
    2a+18 = 40
    2a = 22
    a = 11

    So, the numbers are 11,13,...29
    check:
    5(11+29) = 200

Respond to this Question

First Name

Your Answer

Similar Questions

  1. Math

    A goblin miner earns 1 cent the first day, 2 cents the second day, 4 cents the third day, 8 cents the fourth day. How much will the miner earn in 30 days?
  2. Math

    In a financial deal, you are promised $800 the first day and each day after that you will receive 45% of the previous day's amount. When one day's amount drops below $1, you stop getting paid from that day on. What day is the first …
  3. math

    Mike is saving money for a new bike that costs $180.00. If m represents the amount of money he has saved so far, which expression represents the amount of money, in dollars, he still needs to save?
  4. Math

    Ken started the day with some money in is pocket. After he took some money out of his bank account, he had $4 more than twice the amount he started with. He then received a birthday present which doubled the amount of money he had …
  5. Algebra 1 thx

    Antonia is saving for a video game. On the first day, she saves two dollars in her piggy bank. Each day after that, she doubles the number of dollars she saved on the previous day. How many dollars does she save on the sixth day?
  6. Math

    1. Daniel wants to save at least 20 dollars by putting pennies in a jar daily. On first day, he puts one penny into the jar. The second day he puts 2 pennies into the same jar. On the nth day he pus n pennies into the same jar. Which …
  7. Math

    1. Daniel wants to save at least 20 dollars by putting pennies in a jar daily. On first day, he puts one penny into the jar. The second day he puts 2 pennies into the same jar. On the nth day he pus n pennies into the same jar. Which …
  8. Math Help!

    I apologize for all these questions but I really need to get them done fast so I appreciate if you tried to answer some of them! 1. Bill is saving money in an empty jar. The first day he puts in a certain amount of money. Every day …
  9. Pre-Algebra

    "John puts $200 in his safe and starts saving $50 per month. Write a function rule for the amount of money he will have in his safe after x months. How much money will be in his safe after 12 months?
  10. Social Studies

    How can personal finance decisions affect the economy?

More Similar Questions