Transcript Percentages & Simple Interest Sample Questions

Carpentry & Joinery
Phase 4
Module 2 Unit 5
Percentages & Simple Interest
Sample Questions & Solutions
Carpentry & Joinery
Phase 4
Module 2 Unit 5
Percentages
• Find 32% €180
180
= 100 x 32
= €57.60
Or by calculator = 180 x 32(2nd f)%
= 57.6
= €57.60
Carpentry & Joinery
Phase 4
Module 2 Unit 5
Percentages
• A hardwood flooring supplier dropped his
price for 125mm solid oak flooring from
€48.50 per m² to €43 per m²
• Calculate the % reduction in cost to 2
decimal places
• 48.50 – 43 = €5.50 decrease (change)
5.5
• 48.5 x 100
• = 11.34%
Carpentry & Joinery
Phase 4
Module 2 Unit 5
Percentages
• A sample of timber has an un-dried
weight of 30kg. Its dry weight is 24kg.
• Calculate the % Moisture Content (MC)
– dry weight
• MC = wet weight
x 100
dry weight
• MC = 3024- 24 x 100
6
• MC = 24
x 100
• MC = 25% Answer
Carpentry & Joinery
Phase 4
Module 2 Unit 5
Percentages
• A carpenters gross wage is €450 p/w. He/she has tax
credits worth €238 p/w. Calculate his/her net wage if the
following deductions are made.
Union
€3.40 (tax free)
VHI
€7.60 (tax free)
Tax
21%
PRSI
€3.95
Tax credits
Union
VHI
Gross income = €450 – €238 – €3.40 – €7.60 = €201
Taxable income = €201
201 @ 21% = €42.21 (Tax)
Gross – Deductions = 450 – (42.21 +3.40 + 7.60 + 3.95)
Net Wage = 450 – 57.16 = €392.84
Carpentry & Joinery
Phase 4
Module 2 Unit 5
Percentages
• A roofing job is estimated at €6,200. A breakdown of the costs are
shown below. Calculate the percentage of each element.
Element
Cost
Materials
€2,900
Labour
€2,700
Scaffolding
€600
Answer
2900 ÷ 6200 x 100 = 46.77%
2700 ÷ 6200 x 100 = 43.54%
600 ÷ 6200 x 100 = 9.67%
Carpentry & Joinery
Phase 4
Module 2 Unit 5
Percentages
• A sub-contractor purchases his materials at the local
hardware with a discount of 12%. If the total cost of his
last contract was €1,390 and he spent 30% on materials,
what was the amount of money he saved with discount.
•
•
•
•
•
•
1,390
x 30 = 417
100
So €417 = total paid for materials
100% - 12%(discount) = 88% so 417 = 88% of cost
417 ÷ 88 (%) = 4.74
4.74 x 12 (% discount) = 56.86
= €56.86 (total saving made with materials discount)
Carpentry & Joinery
Phase 4
Module 2 Unit 5
Percentages
• A builder wishes to purchase 15 doors @ €120
each, V.A.T must be paid @ 21%, however, he
receives a discount of 10%. How much does the
builder pay in total ?
15 x 120 = €1800
21% of 1800 = 378
1800 + 378 = €2,178
- 10% = €217.80
2,178 – 217.8
= €1,960.20 Answer
Carpentry & Joinery
Phase 4
Module 2 Unit 5
Simple Interest
• Calculate the interest paid on a loan of
€26,000 over a 5 year term at 8%
• Formula for Simple Interest
(Rate.(in decimals) x Initial amount)term
= (.08 x 26,000)5 = €10,400 Answer
Carpentry & Joinery
Phase 4
Module 2 Unit 5
Profit & Loss
• A building contractor completed a project worth
€280,000. He was left with a profit of €35,000
after all costs 7 overheads were paid
• Calculate the percentage of profit that he made
Number
• Formula: % =
x 100
Total
35,000
•
x 100
280,000
• = 12.5%