SOLUTION: Black pencil cost#15 each and colored pencil cost #21 each if24 mixed pencil costcost #402 how many of them were black

SOLUTION: Black pencil cost#15 each and colored pencil cost #21 each if24 mixed pencil costcost #402 how many of them were black

Algebra.Com

Question 715024: Black pencil cost#15 each and colored pencil cost #21 each if24 mixed pencil costcost #402 how many of them were black
Answer by JBarnum(2146) (Show Source): You can put this solution on YOUR website!
b=black
c=colored
b+c=24
15b+21c=402
Use substitution
b=24-c
15(24-c)+21c=402
360-15c+21c=402
360+6c=402
6c=42
c=7
b=24-7
b=17
17 black pencils
RELATED QUESTIONS
Mr Gorman spent $18 on some paintbrushes and colored pencils. He bought 4 times as many... (answered by lynnlo)

Egg pencils cost $0.15 each and colored pencils cost $0.21 each if 24 pencils cost $4.02... (answered by greenestamps,saw,Alan3354)

If 5 pencil costs 95 cents how much does each pencil cost? (answered by josgarithmetic)

Upon examining the contents of 38 backpacks, it was found that 23 contained a black pen, (answered by edjones)

Upon examining the contents of 38 backpacks, it was found that 23 contained a black pen,... (answered by Edwin McCravy)

A notebook and a pencil cost $40.50.if the notebook cost $30 more than the pencil,what... (answered by addingup)

Vanessa bought 50 pencils for the office. Ten of the pencil cost 50 cents each. Twenty... (answered by richwmiller)

There are 20 colored pencils in a box: 4 red, 5 green, 10 blue, and 1 black. You pick a... (answered by Fombitz)

A book and a pencil cost #410.if the book cost #300 more than the pencil.find the cost of (answered by macston)