Five sisters - alexandra, emily, lisa, martha, and laura decide to purchase a big screen tv as a birthday gift for their mother. - martha agrees to pay 20% of the cost -emily gives $75 -alexandra pays 25% of the cost -laura gives $75 - lisa contributes one-half of the cost. what is the total cost of the big screen tv? what amount will each sister pay?

Step-by-step explanation:

The percentages add to 95%, so the dollar amounts (total $150) comprise 5% of the cost. Then the total cost is ...

  total cost × 5% = $150

  total cost = $150/0.05 = $3000

And the percentages are ...

  20% × $3000 = $600 (Martha's share)

  25% × $3000 = $750 (Alexandra's share)

  50% × $3000 = $1500 (Lisa's share)

Check

$600 + 75 + 750 + 75 + 1500 = $3000 . . . as it should

597

step-by-step explanation:

the surface area is 124cm²

step-by-step explanation:

length: 4cm

width: 9cm

height:   2cm