I keep gettin the wrong answer[ithink] on this math problem.. help??

Question

A math teacher offers to assign homework on the following basis:

1 second of homework the 1st week of school

2 seconds of HW the 2nd week of school

4 seconds of HW the 3rd week of school

8 seconds of HW the 4th week of school

and so on.

If this pattern of doubling continues the entire 36-week school year,

how many MINUTES of homework would you have the last week of the year?

i keep gettin answers in the billions. then when i try to convert to minutes.. i get millions.. i'm pretty sure thts not right.. anyone have any suggestions on how to correctly solve this problem?

THANKS

Answer 1

I came up with 34,359,738,368 seconds.

Equates to 572,662,306.133333 minutes.

9544371.77 hours

397682.16 days

1089.54 years

They sure are long terms in your neck of the woods.

Goes to show that if you play roulette (also 36 numbers) that doubling your bet gets out of hand fairly quickly.

Answer 2

The amount of homework (in seconds) is described by 2^(n-1), where n is the number of weeks of school.  

At 36 weeks it will be 2^35 = 34,359,738,368 seconds.

In minutes, by dividing by 60, that's 572,662,306.133 minutes or 572,662,306 minutes, 8 seconds.

So, you're answer was right.  It's a very big number.  Just shows you what exponential growth will do!

Answer 3

I got 572,662,306.1 minutes.

Answer 4

Don't doubt your math, the number will be huge. Repeatedly doubling a number makes it grow much faster than you'd imagine was possible.

Answer 5

1-1

2-2= 2tothefirst

4-3= 2squared

8-4= 2cubed

16-5= 2^4

32-6

64-7

128-8

256-9

512-10

1024-11

2048-12

4096-13

8192-14

16384-15

32768-16

waste of time....

so then, once you see the pattern that 2 is squared to the # of the week before, we know that 2^35 is the answer in seconds, which has to be converted to minutes.

2^35 = 34359738368 seconds

now i use dimentional analysis (a way to cancel out units)

or just simply divide the ans by 60 bec there are 60 secs in one min

34359738368 sec * (1 min/ 60 sec) = approx. 572,662,306 mins

Answer 6

look at the pattern of numbers 1, 2, 4, 8, .........................

these are the same as powers of 2.

2^0 = 1, 2^1 = 2, 2^2 = 4, 2^3 = 8 .   this sequence continues like this so to find how much homework you will do in the 36th week of school calculate 2^35.

34,359,738,368 seconds which is 572,662,306.13 minutes

Answer 7

I think you are right (or at least on the right track.)   When I did it, I got 5.73*10^8 minutes

Answer 8

you could do it the long way

1,2,4,8,16,32,... or you can do

2^(n-1), where n is the number of weeks so your answer would be

2^35 which is 34,359,738,368 seconds which like you said is millions of minutes, but I believe this is the correct answer