Contemporary Business Mathematics with Canadian Applications 12th edition by S A. Hummelbrunner test

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23) On a trip, a motorist purchased gasoline as follows: 66 litres at 69.0 cents per litre; 69 litres at 70.5 cents per litres;
80 litres at 71.5 cents per litre; and 57 litres at 74.5 cents per litre.
a) What was the average number of litres per purchase?
b) What was the average cost per litre?
c) If the motorist averaged 9.75 km per litre, what was her average cost of gasoline per kilometre?
Answer: a) 66 + 69 + 80 + 57 = 272
Average number of litres = 272 ÷ 4 = 68
b) Average cost per litre:
Total cost = 66 × 69.0 = 45.54
69 × 70.5 = 48.645
80 × 71.5 = 57.20
57 × 74.5 = 42.465
193.85 cents
Average cost = 193.86 ÷ 272 = 71.27 cents
c) Average cost per km = 71.27 ÷ 9.75 = 7.3097436 cents
24) Dorian Frump invested $12 500 in a business on January 1. She withdrew $850 on April 3, reinvested $1920 on
August 1, and withdrew $700 on September 1. What is Don's average monthly investment balance for the year?
Answer: Weighted investment:
January 1 — March 31: 12500 × 3/12 = 3125.0000
April 1 - July 31: 11650 × 4/12 = 3883.3333
August 1 - August 31: 13570 × 1/12 = 1130.8333
September 1 - December 31: 12870 × 4/12 = 4290.0000
Average investment balance = $12429.17
25) Tommy Hughes invested $10 000 in a business on January 1. He withdrew $1000 on March 1, reinvested $5000
on July 1, and withdrew $4000 on October 1. What is Tommy's average monthly investment balance for the
year?
Answer: Weighted investment:
January 1 - February 28: 10000 × 2/12 = 1666.6700
March 1 - June 30: 9000 × 4/12 = 3000.0000
August 1 - August 31: 14000 × 3/12 = 3500.0000
September 1 - December 31: 10000 × 3/12 = 2500.0000
Average investment balance = $10666.67
26) The following information is shown in your investment account for last year. The balance on January 1 was
$7600.00. A withdrawal of $420.00 was made on March 1. A deposit of $1690.00 was made on May 1 and
another deposit of $130.00 was made on October 1. What was the average monthly balance for the year in your
account?
Answer: Date Balance Months Weighted value
January 1 7600 2 15 200
March 1 7180 2 14 360
May 1 8870 5 44 350
October 1 8740 3 26 220
Total: 12 100 130
Average monthly balance = 100130/12 = $8344.17
27) Kevin Ash earns a semi- monthly salary of $1023.40 and works a regular workweek of 40 hours.
a) What is Kevin's hourly rate of pay?
b) If Kevin's gross earnings in one pay period were $1390.47, for how many hours of overtime was he paid at
time and one- half of his regular pay?
Answer: a) Semimonthly pay = $1023.40
Yearly salary = $24 561.60
Weekly gross pay = 24561.60 ÷ 52 = $472.34
Hourly rate = 472.34 ÷ 40 = $11.81
b) Gross pay  = 1390.47
Regular pay  = - 1023.40
Overtime pay  = 367.07
Number of overtime hours = (367.07 ÷ 1.5) ÷ 11.81 = 20.72 hrs.
28) R.J. earns $11.70 an hour, with time- and- a- half for hours worked over 36 a week. His clock hours for a week
are 10.5, 7.5, 11, 13, and 9.75. Determine his gross earnings for a week.
Answer: Total hours = 10.5 + 7.5 + 11 + 13 + 9.75 = 51.75
Regular weekly earnings = 36 × $11.70 = $421.20
Overtime earnings = (51.75 - 36) × $11.70 × 1.5 = $276.41
Gross = Regular time + Overtime = $421.20 + $276.41 = $697.61
29) Florence Lamb is paid a commission of 10 3/4% on her net sales and is authorized to draw up to $900.00 a
month. What is the amount due to Florence at the end of a month in which she drew $820.00, had sales of $14
660.00, and sales returns of $331.20?
Answer: Gross sales  = $14660.00
Less: returns  = 331.20
Net sales  = 14328.80
Gross commission = 14328.80 × .1075 = 1540.35
Less: drawings  820.00
Amount due  $720.35
30) A sales representative selling computer parts receives a commission of 3.5% on net sales up to $15 000.00, 7% on
the next $6000.00, and 9% on any further sales. If his sales for a month were $34 250.00 and sales returns were
$1055.00, what was his commission for the month?
Answer: Gross sales  = $34250.00
Less: returns  = 1055.00
Net sales  = $33195.00
Commission: = .035 × 15000.00 = $525.00
= .07 × 6000.00 = 420.00
= .09 × 12195.00 = 1097.55
Total commission = $2042.55
31) A salesperson had gross earnings of $943.25 for last week on gross sales of $8320.00. If returns and allowances
were 5.5% of gross sales, what is his rate of commission based on net sales?
Answer: Net sales = (1 - .055) * 8320 = 7862.40
Commission rate =
943.25
7862.40