Question

1) Kim was hired to paint a house. it took 35 hours to paint and she was paid $840. at this rate, how much would she be paid for a job required 90 hours of work? round answer to nearest hundredth

2) if 4 pounds of meat serves 9 people, how many pounds will be needed to serve 30 people? round answer to nearest hundredth

3) how much interest will you earn if you invest $1225 at a rate of 6% a year for 33 months?

4) how much money did jonah invest if he received $315 in interest after 51 months? the interest rate was 7% a year. round answer to nearest hundredth

Answer 1

Part 1) Kim was hired to paint a house. it took 35 hours to paint and she was paid $840. at this rate, how much would she be paid for a job required 90 hours of work? round answer to nearest hundredth

we know that

by proportion

`(840)/(35) (\$)/(hours) =(x)/(90) (\$)/(hours)\\ \\35*x=840*90\\ \\x=(840*90)/35\\ \\x=\$2,160`

therefore

the answer part 1) is

`\$2,160`

Part 2) if 4 pounds of meat serves 9 people, how many pounds will be needed to serve 30 people? round answer to nearest hundredth

we know that

by proportion

`(4)/(9) (pounds)/(people) =(x)/(30) (pounds)/(people) \\ \\9*x=4*30\\ \\x=(4*30)/9\\ \\x=13.33\ pounds`

therefore

the answer part 2) is

`13.33\ pounds`

Part 3) how much interest will you earn if you invest $1225 at a rate of 6% a year for 33 months?

we know that

The simple interest formula is equal to

`I=P(rt)`

where

I is the Final Interest amount

P is the Principal amount of money to be invested

r is the rate of interest

t is Number of Time Periods in years

in this problem we have

`t=33/12\ years\\ P=\$1,225\\r=0.06`

substitute in the formula above

`I=\$1,225*(0.06*33/12)=\$202.13`

therefore

the answer Part 3) is

`\$202.13`

Part 4) how much money did jonah invest if he received $315 in interest after 51 months? the interest rate was 7% a year. round answer to nearest hundredth

we know that

The simple interest formula is equal to

`I=P(rt)`

where

I is the Final Interest amount

P is the Principal amount of money to be invested

r is the rate of interest

t is Number of Time Periods in years

in this problem we have

`t=51/12\ years\\ I=\$315\\r=0.07`

substitute in the formula above

`I=P(rt)`

solve for P

`P=I/(rt)`

`P=\$315/(0.07*51/12)=\$1,058.82`

therefore

the answer Part 4) is

`\$1,058.82`