She will then have 3 rings
Answer:
the answer is about 1.2
Step-by-step explanation:
Answer:
A
Step-by-step explanation:
1.3 times.45+1.3
Answer:
Step-by-step explanation:
Given the explicit function as
f(n) = 15n+4
The first term of the sequence is at when n= 1
f(1) = 15(1)+4
f(1) = 19
a = 19
Common difference d = f(2)-f(1)
f(2) = 15(2)+4
f(2) = 34
d = 34-19
d = 15
Sum of nth term of an AP = n/2{2a+(n-1)d}
S20 = 20/2{2(19)+(20-1)15)
S20 = 10(38+19(15))
S20 = 10(38+285)
S20 = 10(323)
S20 = 3230.
Sum of the 20th term is 3230
For the explicit function
f(n) = 4n+15
f(1) = 4(1)+15
f(1) = 19
a = 19
Common difference d = f(2)-f(1)
f(2) = 4(2)+15
f(2) = 23
d = 23-19
d = 4
Sum of nth term of an AP = n/2{2a+(n-1)d}
S20 = 20/2{2(19)+(20-1)4)
S20 = 10(38+19(4))
S20 = 10(38+76)
S20 = 10(114)
S20 = 1140
Sum of the 20th terms is 1140
The 114 represents 80% of the total price before the sale. You would set up your equation as
Cost Price * 80% = Sale Price.
Sale Price = 114
80% = 80/100 = 0.8
Cost Price = 114/0.8
Cost Price = 142.50 which is the price before the deduction. You can confirm this by taking 20% of 142.50 and subtracting it form 142.50
20% * 142.50
20/100 * 142.50
2850/100
28.50
Now subtract 28.50 from 142.50
142.50 - 28.50 = 114 which is just what you might expect.
