Tina lost 3 pounds on the first week of her diet. She gained a pound on the second week, and then lost 2 pounds a week during every week afterwards. She has been dieting for a total of 13 weeks. How many pounds has Tina lost in all?
A. 26 pounds
B. 20 pounds
C. 24 pounds
D. 22 pounds

Question

Tina lost 3 pounds on the first week of her diet. She gained a pound on the second week, and then lost 2 pounds a week during every week afterwards. She has been dieting for a total of 13 weeks. How many pounds has Tina lost in all?
A. 26 pounds
B. 20 pounds
C. 24 pounds
D. 22 pounds

kittiwitti1 · Answer

lost 3 pounds: -3
gained 1 pound: +1
lost 2 pounds every week after: 2n (n is the consecutive weeks)
Thirteen weeks minus two weeks is eleven weeks. So n is 11.
Equation:$$-3+1-2n\rightarrow-3+1-2(11)=?$$

kittiwitti1 · Answer

Are you still lost?

anonymous · Answer

yup

kittiwitti1 · Answer

Where are you confused?

anonymous · Answer

i suck at math so all of it and i doing at home school so i don't really have a teacher to help me or teach me how to do any of this

anonymous · Answer

im gonna guess 24

kittiwitti1 · Answer

1st week: lost 3 pounds. Lost means subtract, -3.
2nd week. gained 1 pound. Gain means add, +1
the other weeks: lost 2 pounds each. Lost means subtract. Since the first two weeks are of a different weight gain/loss, we subtract the first two weeks from the total 13 weeks and get 11 weeks, 13-2=11 weeks.

So basically$$\text{week one}-3,\text{week two}+1$$$$\text{the remaining weeks}13-2=11\text{ weeks}\rightarrow-2n\text{with n being # of weeks}$$$$\text{since n is 11, }-2n=-2(11)\rightarrow\text{add it all up and }-3+1-2(11)$$

kittiwitti1 · Answer

Maybe my explanation was confusing. But the equation you get to find the answer is -3+1-2(11)

kittiwitti1 · Answer

$$-3+1-2(11)=-3+1-22=-25+1=-24$$You got it right, except it was negative. :]