Question

Solve the proportion for N:

5/12 = 35/N

7/18 = N/9

An electrician pays 2/5 of the amount he charges for a job for supplies. If he was paid $240 for a certain job, how much did he spend on supplies?

Bright Ideas purchased 1,000 lightbulbs. Headlight bulbs cost $13.95 each, and taillight bulbs cost $7.55 each. If Bright Ideas spent $9,342 on lightbulb stock, how many headlights and how many taillights did it get? What was the dollar value of the headlights ordered? What was the dollar value of the taillights ordered?

If 5 dozen roses can be purchased for $62.50, how much will 8 dozen cost?

Answer 1

For the first three questions
5/12 = 35/N
Rearrange: N = 35 / (5/12) = ( 35 / 0.4167 ) = N = 83.99

7/18 = N / 9
Rearrange: N = (7/18)* 9 = 3.5

(2/5) * 240 = 96
He spent $96 on supplies

Answer 2

$1.\rightarrow \frac{5}{12}=\frac{35}{N}\\\\\rightarrow 5N=35 \times 12\\\\\rightarrow N=\frac{420}{5}\\\\\rightarrow N=84\\\\2.\rightarrow \frac{7}{18}=\frac{N}{9}\\\\\rightarrow 18N=7 \times 9\\\\\rightarrow N=\frac{63}{18}\\\\\rightarrow N=\frac{7}{2}\\\\N=3.5\\\\3.\text{Amount paid for the job}=240\\\\\text{Amount spent on supplies}=240 \times \frac{2}{5}\\\\=48 \times 2\\\\=96$

---Amount spent on supplies if electrician pays two fifth of the amount he charges for a job for supplies =$ 96

4.

h=Headlight

t=Taillight

→h+t=1000------(1)×13.95

→13.95 h +13.95 t=13950-----(1)

→13.95 h+7.55 t=9342------(2)

equation (1) - equation (2)

  6.40 t=4608

t=720------(Taillight Bulb)

Replacing ,t by 720 in equation 1,

h+720=1,000

h=1,000 -720

h=280---(Headlight bulbs )

→5.

Cost of 5 dozen of roses =$62.50

Cost of a dozen of rose=$ 12.50-----Dividing both sides by,5

Cost of 8 dozen of rose=$ 12.50 × 8----Multiplying both sides by,8

       =$ 100.00