posted by Bethany
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 day is the first day on which he has at least 20 dollars in thejar? (1 dollar=100 pennies) a. 60 b. 61 c. 62 d. 63 e. 64
I tried the sum equation but I got 1334 which is no one of the choices.
2. The first term of a sequence is 12, and each term after the first is 2 less than the preceding term. If n is a positive integer, which of the following could be the sum of the first n terms of the sequence? a. -14 b. -2 c. 28 d. 31 e. 81
3. "123...91011...3" If the positive integers(to the left) are written one after another as shown until the eighth occurence of the digit 3, how many digits are in the number? a. 29 b. 33 c. 39 d. 48 e. 57
4. 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?
5. The sum of 4 consecutive odd integers is 48. What is th largest of the four integers?
How do you set up this kind of consecutive equation when using x, x+2, x+4 etc.?
if the first odd integer is 2k+1, then the others are 2k+3,2k+5,2k+7
So, adding them up you get 8k+16=48
the numbers are 9,11,13,15
Your idea is also good, but to guarantee odd numbers, you need even numbers+1. In some situations you might get a solution for x but find that x is not odd.
Oo I see! ThanksSteve! Could you Lso hep me with the questions above?