For the arithmetic sequence
a₁, a₂, a₃, ...,
the n-th term is
where d = the common difference
Because a₅ = 12.4,
a₁ + 4d = 12.4 (1)
Because a₉ = 22.4,
a₁ + 8d = 22.4 (2)
Subtract (1) from (2).
a₁ + 8d - (a₁ + 4d) = 22.4 - 12.4
4d = 10
d = 2.5
From (1),
a₁ = 12.4 - 4*2.5 = 2.4
Therefore
a₃₁ = 2.4 + 30*2.5 = 77.4
Answer: a₃₁ = 77.4
Given:
price = 1,250
sales discount = 15%
sales tax = 6.5%
The problem is unclear whether the price is the original price or the discounted price. I am assuming that the price is the original price.
Original price times sales discount rate is the value of sales discount
1,250 x 15% = 187.50
Original price less the value of sales discount is the discounted price.
1,250 - 187.50 = 1,062.50
Discounted price times sales tax rate is the value of the sales tax
1,062.50 x 6.5% = 69.06
Discounted price plus sales tax is the total cost of the purchase
1,062.50 + 69.06 = 1,131.56
10 x 62 is the equation for this problem because every row has 62 and there are 10 rows.
Answer:
Volume=355 cm³
Step-by-step explanation:
I assume it should be 10 cm, not 10 m. If it is 10 m, everything will have to be adjusted.
Circumference = 2
r
10=2r
10÷2=r
1.59=r
V=r²h
V=(1.59)(71)
v=355
Let Lisa's height be x, Ian's be y and Jim's be z
x = 10 + y . . . (1)
y = 14 + z . . . (2)
y + 14 + z + 14 = 170 + x + 14
y + z - x = 170 + 14 - 28 = 156 . . . (3)
From (2), z = y - 14 . . . (4)
Putting (1) and (4) into (3) gives,
y + y - 14 - 10 - y = 156
y = 156 + 24 = 180
Therefore, Ian's height is 180 centimeters
