Answer:
Step-by-step explanation:
<u>Given</u>
<u>Converted to standard form</u>
- 8*10^-7 = 8*0.0000001 = 0.0000008
Well, for the first question, the answers will be (a) 13 per row, because 13*13=169, and (b) a square, because the dimensions will be 13x13.
Try this solution (note, this is not the shortest way):
1. if the given length is 'l' and the width is 'w', then according to the condition 4*l=w;
2. according to the condition the perimeter is 30 ft. Formula of the perimeter is P=2(l+w), then 2(l+w)=30;
3. if to substitute '4*l' instead of 'w', the formula of the perimeter (from item no. 2) will be as 2(4*l+l)=30 or 10*l=30 ⇒ l=3 ft. The length is 3 ft.!
4. if l=3 ft., then w=4*3=12 ft. The width is 12 ft.!
5. Area is
A=w*l; A=12*3=<u>36 ft²</u>
The flat screen TV that is marked up by 30% and 20% discount had a profit of $60 after being sold.
The mark up percentage is given by:
Mark up percentage = (selling price - cost price)/cost price
Since the original price is $1500, hence:
30% = (selling price - 1500)/1500
0.3 = (selling price - 1500)/1500
(selling price - 1500) = 450
Selling price = $1950
It was again sold at a discount of 20%:
Final selling price= 1950 - 20% of 1950 = 1560
Profit = 1560 - 1500 = $60
Hence $60 profit was made by the store for the sale of a flat screen TV.
Find out more at: brainly.com/question/15699405
Answer:
a) 820
b)450
c) -540
d) -294
e) 1440
f) 1425
Step-by-step explanation:
a) it is an arithmetic progression with ratio=4
a1=3,
a2=3+r=3+4=7.....
a20=a1+19r
so a20=3+19*4=3+76=79
S=(a1+an)*n/2 where n=20
so S=(3+79)*20/2=820
b) a15=a1+14*r=2+14*4=2+56=58
S=(a1+a15)*15/2=(2+58)*15/2=60*15/2=30*15=450
It is the same formula for all the exercises
S=(a1+an)*n/2 , where n is the number of terms
c) a40=30+39*(-3)=30-87=-57
So S=(30-57)*40/2=-540
d) a14=5+13*(-4)=5-52=-47
S=(5-47)*14/2=-42*14/2=-42*7=-294
e) it is 5+7+9+......+75
nr of terms = (an-a1) :r+1=(75-5):2+1=36
S=(5+75)*36/2=36*40=1440
f) ratio=7-4=3
the same formula for n= (91-4):3+1=87:3+1=29+1=30
S=(4+91)*30/2=95*30/2=2850/2=1425
