Find the cost price if the selling price is $1800 and profit is $10%

$1636.4

Step-by-step explanation:

Selling price(sp)=$1800

Profit%=10%

Cost price(cp)=?

Profit%=(sp-cp)/cp x 100

10=(1800-cp)/cp x 100

Cross product

10cp=100(1800-cp)

Open brackets

10cp=180000-100cp

Collect like terms

10cp+100cp=180000

110cp=180000

Divide both sides by 110

110cp/110 = 180000/110

cp=1636.4

Cost price is $1636.4

Cost Price = $1, 636.36

Step-by-step explanation:

Given from the question Selling price (SP)= $1800; Profit%= 10%= 10/100 = 0.1

Cost price(CP)= ??

Profit% is derived by the formula

=(SP-CP)/ CP x 100

0.1 = (1800 - CP)/CP x 100

Then we cross multiply

0.1 x 100 x CP = 1800 - CP

10 CP = 100(1800 - CP)

Open the bracket

10 CP=180000 - 100CP

Divide both sides by 10

CP = 180000 - 100CP/10

CP = 18000 - 10CP

Combine like terms

CP + 10CP = 18000

11CP = 18000

Divide both sides by 11

CP = 18000/11

CP = $1, 636.36

walter needs to make at least 5 more cookies but no more than 40. 5 ≤ x ≤ 40

step-by-step explanation:

20 ≤ x + 15 ≤ 55

subtract 15 from all parts

20-15 ≤ x + 15-15 ≤ 55-15

5 ≤ x ≤ 40

this means how many more cookies he has to make

walter needs to make at least 5 more cookies, but no more than 40 cookies; 5 ≤ x ≤ 40