2 math questions?

Question

1) when Courtney collected her change she realized that she had 5 times as many dimes as quarters. Her dimes and quarters totaled $5.25. How many quarters did she have>

2) A store manager bought "c" calculators for $8 each.All but 4 were sold for $10 each, The remaining four calculators were not sold. Find the store's profit in terms of "c".

thanks for helping. :)

Answer 1

1.) 7 quarters..... 7 quarters=1.75 + 35 dimes= 3.50
1.75+3.50 =5.25

2.) I have no idea!!

Answer 2

1) 5.25 = Q + 5*(Q/2.5), where Q represetns the value of the quarters and Q/2.5 is the value of the dimes. Then
5.25 = 3Q, or Q =1.75. So there are 7 quarters and 35 dimes.

2) Total cost = 8c; revenue = 10 *(c -4) = 10c - 40.
Profit = 10c - 40 - 8c = 2c - 40, with 4 items in inventory.

Answer 3

D = number of Dimes, Q= number of Quarters
D=5xQ (number of Dimes =5 times the number of quarters)
0.25xQ +0.10xD = $5.25
substitute 5xQ for D
0.25Q+0.10x5xQ = $5.25
0.25Q+0.5Q=$5.25
0.75Q=$5.25
Q= 5.25/0.75 = 7 quarters
there D = 5x7 = 35
35 x 0.10 + 7 x 0.25 = $5.25

Cost to store = c x $8
Sales = (c - 4) x $10
Profit = (c - 4) x $10 - c x $8
Profit =10c-40-8c
Profit = 2c - $40

Answer 4

let d=dimes and q=quarters. if she had 5 times as many dimes as quarter then d=5q.
d+q=$5.25, change everything into cents
10d+25q=525 then put 5q in place of d
10(5q)+25q=525
50q+25q=525
75q=525
q=7
the numbers of quarter is 7

#2
if the he brought c calculator for $8 each, sold 4 for $10 and 4 were not sold then it means that he initially brought 8 calculators.
4 sold + 4 not sold = C
Profit= sale price-purchase price
P= (8x10)-(8x8)
P=80-64
P=16 however half were sold,
P=16x1/2
P=8

Answer 5

1.) 7 Quarters and 35 dimes.

2.) Profit = (10C - 40) - 8C

Answer 6

1) 7 quarters + 35 dimes = $5.25

2) Facts 8c (calculators) = n (money paid)

and 10(c-4) = a (money made)

so [10(c-4)] - (8c) = p (profit)

therefore... looks like to me that's as close as you can get? Not really sure though... been a while since I've done algebra word problems... lol. but thanks for the brain work out anyways....

Answer 7

x= # of quarters
5x = # of dimes
.25*x +.1*5x = 5.25
.75x=5.25
x = 7 = # of quarters
5x = 5*7=35 = # of dimes

Cost = 8c
Revenue = 10(c-4) = 10c-40
Profit = revenue -cost = 10c-40 -8c = 2c-40

Answer 8

1. nitroboatman is correct.

2. There isn't enough information to supply an answer.