Answer:
-125
Step-by-step explanation:
Each term is 7 less than the previous term.
1st term: 15
2nd term: 15 - 7
3rd term: 15 - 7 - 7 = 15 - 2(7)
4th term = 15 - 7 - 7 - 7 = 15 - 3(7)
Notice that each term is 15 minus a multiple of 7. The multiple is obtained by multiplying 7 by 1 less than the term number.
The formula is:
For the 21st term, multiply 7 by 20, and subtract from 15.
7 × 20 = 140
15 - 140 = -125
Using the formula:
Answer: -125
by unitary method the exact answer is correct (2,920 glasses).
given, glasses of water each day = 8
therefore, by unitary method :
glasses of water in 365 day =
hence the total glasses of water in 365 days = 2,920
learn more about unitary method here:
#SPJ9