Math

Janson bought 7 identical pens and had \$4.20 left. He could have bought 10 pens with all his money. How much did Janson have?

1. 👍
2. 👎
3. 👁
1. \$4.20 is 3/10 of what he had ... (10 - 7) / 10

\$4.20 / .3 = ?

1. 👍
2. 👎
2. Let Y = cost of each pen
10Y = 7Y + 4.20
3Y = 4.20
Y = 1.40 = cost of each pen; therefore,
10 pens@ 1.40 each = \$14.00 is how much money Ben had initially.

1. 👍
2. 👎
👤
DrBob222

Similar Questions

1. math

At an office supply store, Samantha bought 5 notebooks and 2 pens for \$9. Jeffrey bought 3 notebooks and 2 pens for \$6. Find the price of a notebook and the price of a pen. (please help I'm stuck)

2. math

A shopkeeper bought pens at a rate of 12 pens for 150 rs and sold them at rate of 10 pens for 130rs.The number of pens he should sell to earn a net profit of 20rs is?

3. Pre-Calc

How do you do this? A farmer has 336 feet of fencing and wants to build two identical pens for his prize-winning pigs. The pens will be arranged as shown. Determine the dimensions of a pen that will maximize its area.

4. Algebra

You plan to build four identical rectangular sheep pens in a row. Each adjacent pair of pens share a fence between them. You have a total of 368 feet of fence to use. Find the dimension of each pen such that you can enclose the

1. Math

A pencil costs \$3.50 and a pen costs \$6.70. Jessica bought m pens. She also bought 4 fewer pencils than pens. Write an algebraic expression for the total amount she spent. The answer supposed to be 6.70m + 3.5 (m-4). I got

2. math

jared bought a package of pens containing 20 pens. If 3/4 of the pens had black ink, how do you determine the number of pens with black ink?

Suppose C(x)=x^2−6x+20 represents the costs, in hundreds, to produce x thousand pens. How many pens should be produced to minimize the cost? What is the minimum cost? Number of pens to minimize cost: Minimum Cost:

A farmer has 100 yards of fencing to form two identical rectangular pens and a third pen that is twice as long as the other two pens, as shown in the diagram to the right. All three pens have the same width, x. Which value of y

1. Calculus BC

A farmer has 100 yards of fencing to form two identical rectangular pens and a third pen that is twice as long at the other two pens, as shown in the diagram at right. All three pens have the same width, x. What value of y

2. Algebra

Gerry had a total of 30 pens and pencils. He decided to trade with his friends all of his pens and pencils. If he traded every pen for 2 pencils, he would have 48 pencils in all. How many pens and how many pencils did he have

3. math,(fraction)

Mr Lim put some red pens and blue pens into a box.The ratio of the number of red pens to the number of blue pens was 3:4. He added 20 red pens into the box and the ratio became 2:1. a. were there more red pens or blue pens in the