oscar math assignment

7/30/2019 Oscar Math Assignment

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Exercise No.1

Belen Garcia

EDUC 1082

Mr. Nestor Chan

February28, 2010


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Assignment 1

1.) A business woman bought a refrigerator from a manufacturer for $1,378. Calculate:

a.) The selling price if she makes a profit of 17.5 %.

Cost Price = $1,378

Selling Price = 117.5 % of $1,378

= 17.5 x $1,378

100

= $241.16

Selling Price = CP + Profit

= $1,378 + 241.16

Selling Price = $1619.15

b.) The selling price if she makes a loss of

Selling Price = 3.5% of $1,378

= 3.5 x $1,378

100

= $48.23

Selling Price = Cost Price Loss

=$1,378 - 48.23

Selling Price = $1,329.77

2.) A persons weight increased by 12% between the tenth and fourteenth birthday. If the

person weighed 45 kg on the tenth birthday, what was the weight on the fourteenth

birthday?

Weight = 45 kg

New Weight = (12 % of 45) + 45

= (.12 x 45) + 45

= 5.4 + 45

= 50.4 kg


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3.) When fuel was $2.40 a gallon, I used 1,200 gallons per annum. The price increased

by 150%, so I decreased my yearly consumption by 25 %. Find:

a.) The new price per gallon of fuel. Using ratio

100% = $2.4

150% = x

Cross multiply 100% x = $2.4 x 150

Cost Price = ( $2.4 x 150) + 2.4

100

= (3.6) + 2.4

= $6.00

b.) Reduced annual consumption

100% - 25% = 75%

100% = $1,200

75% = x

100x = .75 of 1,200

= (.75 x 1200)

= 900 gallons

c.) New Bill = New Cost x Reduced Annual Consumption

= $6 x 900

= $5,400

Difference = New Bill - Old Bill

= $5,400 - $2,880

= $2,520 more

4.) After a 4% increase, an accountants salary was $7,280. Calculate the salary if a 10%

increase was given instead.

Using ratio 104% = $7,280

110% = x

1.04 x = $7280 x 1.10

x = 7280 x 1.10

1.04

salary at 10%increase = $7,700


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5.) After a 20% increase, a physicists salary was $7,200. Calculate the physicists salary

if a 25% increase was given instead.

Using ratio 120% = $7200

125% = x

1.20x= 1.25 x $7200

x = 1.25 x 7200

1.20

Salary at 25 % increase = $7500

6.) Mr. Ricky borrowed $5,340 from a bank at 9.5% per annum simple interest for 5

years. Determine:

a.) The sum of money paid as interest to the bank.

SI = PRT/100 = $5,340 x 9.5 x 5

100

= $2,536.50

b.) The total amount repaid to the bank.

Amount = $5,340 + $2,536.50

= $7,876.50

c.) What was Mr. Rickys monthly installment to the bank?

Monthly Installment = $7,876.50

[ 5 x 12] = 60

= $131.28 per month

7.) Calculate the rate percent per annum if $250 simple interest is paid when $800 is

invested for 5 years.

SI = PRT

100

250 = 800 x Rate x 5

100

250 = (800x 5) R

100


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250 = 4000 R

100

250 = 40R

40

250 = R

40

Rate = 6.25 %

8.) $6,000 was put in a fixed deposit account on 1st January, 2005 for 6 months. The rate

of interest was 7.5% per annum. On 1st July, 2005 the total amount accumulated so far

was reinvested at 7% per annum for a further 6 months. Calculate the final amount

received at the end of the year.

SI = PRT

100

SI = 6000 x 7.5 x 0.5

100

SI = $225

Amount = $225 + $6,000

= $6,225

SI = PRT

100

SI = 6,225 x 7 x 0.5

100

SI = $217.88

Final Amount = $6,225 + $217.875

= $6,442.88

9.) A television can be bought on hire purchase by paying a down payment of $850 and

18 monthly installments of $195 each.

a.) Calculate the hire purchase price.

HP = $850 + ($195 x 18)

= $4,360


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b.) If it is bought on cash, it can be gotten for 75% of the hire purchase price. Calculate

the cash price for the television.

Cash Price = 75% x 4360

= .75 x 4360

=$3270

10.) How many units of electricity would a 75 W bulb use in 100 hours?

Kwh = W x h

1000

= 75 x 100

1000

= 7.5 Kwh

11.) Calculate the number of kwh a 225 W freezer use in 168 hours.

Kwh = W x h

1000

= 225 x 168

1000

= 37.8 Kwh

12.) Electricity rates are as follows:

$0.34 for the first 50 Kwh

$0.45 for the next 100 Kwh

$0.55 for the next 150 Kwh

$0.60 for any Kwh thereafter

a.) Calculate Mr. Rabannis electricity bill if the previous reading was 80,759 and the

present reading is 82,796.

Kwh used = 82,796 80,759

= 2,037 Kwh

50 x $0.34 = $ 17.00


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100 x $0.45 = $ 45.00

150 x$0.55 = $ 82.50

1,737 x $0.60 = $1,042.20

2,037 kwh = $1,186.70

Mr. Rabannis Bill = $1,186.70

b.) Calculate how much he will be refunded if the company is ordered to return 15.5% of

this months bill to customers?

Refund = 15.5% x $1,186.70

= 15.5 x 1186.70

= $183.94

oscar math assignment

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