Please solve the following 3 word problems

Question

Write an inequality, but do not solve

 

1.  The high temperature for the day is predicted to be 86 degrees F.  Use the formula F = 9/5C + 32 to write an inequality in degrees Celsius for the range of temperatures predicted.

 

2.  The salinas brothers, Juan and Carlos, have collected pledges for a bike rally they plan to have to raise money for their boy scout troop.  Carlos's pledges total $11.50/mi and Juan's pledges total $9.75/mi.  carlos can peddle 10 mi/hr and Juan can peddle 12 mi/hr.  If they plan to start and stop at the same time, how many hours will they have to bike if they want to raise at lease $1000 together?

 

 

Write an inequality and solve

 

3.  Asha feels she needs $45,000 per year in retirement.  If she receives $2,500 a month from Sopcial Security, at what interest rate must Asha invest her $250,000 of savings for her income to be at lease $45,000 per year?

Answer 1

F=(9/5)C+32

86=(9/5)C+32

86-32=(9/5)C

54=(9/5)C

(5/9)(54)=(5/9)(9/5)C

30=C

C=(5/9)(F-32)

(5/9)(F-32)<30

 

($11.50)(10)(h)+($9.75)(12)(h)>$1000 where h=# of hours

 

Assuming simple interest...

 

($250,000)(r)+($2500)(12)>$45,000

($250,000)(r)+($30,000)>$45,000

($250,000)r>$45,000-$30,000

($250,000)r>$15,000

r>$15,000/$250,000

r>15/250

r>3/50

r>6/100

r>6%