Respuesta :
Answer:
Correct answer: pt = 7,000 minutes
Step-by-step explanation:
This is arithmetic series:
p₁ = 40 min
p₂ = p₁ + 20
p₃ = p₂ + 20 = p₁ + 2 · 20
p₄ = p₃ + 20 = p₁ + 3 · 20
...........................................
pₙ = p₁ + (n - 1) · 20
25 - th day will be practicing:
p₂₅ = 40 + 24 · 20 = 520 minutes
The total sum of the arithmetic series is calculated according to the following formula:
Sₙ = (n/2) (p₁ + pₙ)
In 25 days he will have practiced total minutes
pt = (25/2) · ( 40 + 520) = (25/2) · 560 = 7,000 minutes
pt = 7,000 minutes
God is with you!!!
Answer: he would have practiced for 7000 minutes in 25 days.
Step-by-step explanation:
His practice time is increasing in arithmetic progression each day. The formula for determining the sum of n terms of an arithmetic sequence is expressed as
Sn = n/2[2a + (n - 1)d]
Where
n represents the number of terms in the arithmetic sequence.
d represents the common difference of the terms in the arithmetic sequence.
a represents the first term of the arithmetic sequence.
From the information given,
a = 40 minutes
d = 20 minutes
For minutes practiced in 25 days,
n = 25
Therefore, the sum of the first 25 terms, S205 would be
S25 = 25/2[2 × 40 + (25 - 1)20]
S25 = 12.5[80 + 480)
S25 = 12.5 × 560 = 7000