# Thread: Some Quick Questions for my Exam

1. ## Some Quick Questions for my Exam

Hello! I obviously don't mean for my exam. I mean some questions i want to cover for my studying for the exam. They may seem easy to you, but were not all blessed with gifts in Mathematic's so here they are in easy order These following questions are jusr questions that may be represented in the exam i'm told. So i'm just practising.

How would this happen? 6d-7d+2d=
You can’t take 7 out of 6
And: 3x-9x-4x+10xy =
Is there something I’m missing?

Okay a Sausage Company may legally contain 32% fat, a 0.8 kg pack contains 260g of fat, another top seller, 2 kg packs of Beaut Beef Contains 610g of fat.
- What is the Legal amount of fat that is allowed in both types?
-Which Sausage meets the requirement and by how many grams?

Car Priced at $26 000 deposit of 10% is to be paid at an interest of 8% charged on balance, to be paid in equal monthly instalemtns over 5 years - How much Deposit -What amount oweing on the car -Calculate the interest using Simple Interest Formular -What monthly Instalments? Okay the formular is: SI= PxRxT/100 = 26,000 x 10%x 5/100 is that right? and lastly Ben is able to display 1775 stamps. This number represents 15% of total stamp collection, estimate to the nearest 100. 2. Originally Posted by Sazza How would this happen? 6d-7d+2d= You can’t take 7 out of 6 Actually, you could take 7 out of 6, but let's not worry about that for now. We can add and subtract in any order, addition and subtraction is commutative. so we can add the 6 and the 2, and then subtract the 7 And: 3x-9x-4x+10xy = Is there something I’m missing? Do you have something missing? Maybe, maybe not (there may be a typo). but this is a workable problem, just add all the x terms together. 3x - 9x - 4x + 10xy = -10x + 10xy or if you prefer, you can factor out the 10x to get: 10x(y - 1) 3. Originally Posted by Sazza Okay a Sausage Company may legally contain 32% fat, a 0.8 kg pack contains 260g of fat, another top seller, 2 kg packs of Beaut Beef Contains 610g of fat. - What is the Legal amount of fat that is allowed in both types? -Which Sausage meets the requirement and by how many grams? The company should contain 32% fat, or the products that the company makes? Ok. You need your knowledge of conversion factors here. 1 kg = 1000 g so 0.8 kg = 800 g and 2 kg = 2000 g what percentage of the product of the first company is fat? $\mbox {Percent fat} = \frac { \mbox {Grams of fat}}{ \mbox {Total grams of product}} \times 100$ So for the company with the 0.8 kg pack: $\mbox {Percent fat} = \frac {260}{800} \times 100 = 32 \frac {1}{2}$ % for the company with the 2 kg pack: $\mbox {Percent fat} = \frac {610}{2000} \times 100 = 30 \frac {1}{2}$ % Can you answer the questions now? 4. Yeah i sure can: The company which contain's 0.8kg of fat holds the largest percentage of fat: % 5. Originally Posted by Sazza Yeah i sure can: The company which contain's 0.8kg of fat holds the largest percentage of fat: % Umm, that's not answering the question. The question is: Originally Posted by Sazza - What is the Legal amount of fat that is allowed in both types? -Which Sausage meets the requirement and by how many grams? 6. -Well the legal amount is: 32% is allowed in both types? - The Company which contain's 2 kg would be more ideal because it contain's 30.5% but the company which contains 0.8 went over by 1/2 g right? 7. Originally Posted by Sazza -Well the legal amount is: 32% is allowed in both types? - The Company which contain's 2 kg would be more ideal because it contain's 30.5% but the company which contains 0.8 went over by 1/2 g right? yes for the first question (that question was kind of trivial, make sure you don't have a typo there). for the second question, you are half right. the company with the 2 kg pack is in line with the legal limit. but the company that goes over, goes over by 2 percent, not 2 grams. you have to find how many grams is that 2 percent. but the question didn't ask you about that company, it asked you about the company that fulfilled the requirement (again, this may be a typo, since it would be weird to say "they made the requirement by this much", a better question is, for the company that failed to fulfill the requirement, by how many grams of fat did they go over?) 8. Originally Posted by Sazza Car Priced at$26 000 deposit of 10% is to be paid at an interest of 8% charged on balance, to be paid in equal monthly instalemtns over 5 years
- How much Deposit

the deposit is 10% of the original. remember i told you a while ago that "of" means "multiply" and "%" means "over 100"

So, Deposite = 10% of 26000 =
$\frac {10}{100} \times 26000 =$ ?
-What amount oweing on the car

This is just the total amount minus the deposit

-Calculate the interest using Simple Interest Formular

$\mbox {Simple Interest} = \mbox {Principal} \times \mbox {Rate} \times {Time}$

Here, Principal = the amount owed, which you calculated in the second question

Rate = 8% = 8/100 = 0.08

Time = 60 months

-What monthly Instalments?
The monthly installment is the amount paid per month

$\mbox {Monthly installments} = \frac { \mbox {Total Amount Paid}}{ \mbox {Number of Months}} = \frac { \mbox {Balance} + \mbox {Interest}}{ 60 \mbox { months}}$

9. Originally Posted by Sazza
Ben is able to display 1775 stamps. This number represents 15% of total stamp collection, estimate to the nearest 100.
Ok, let x be the number of stamps in the total collection (which i think is what you wanted to find, though you never actually said so).

1775 is 15% of x

can you set up an equation to solve for x? show me

10. 1775 x 15% x X (number of stamps)

Well i used the calculator just to see what would come up, because usually that can be used for percentage, and when your doing the simp interest formula. I got 266

11. Originally Posted by Sazza
1775 x 15% x X (number of stamps)
No, "is" does not mean "multiply", is means "equal," and write 15% as a fraction

Well i used the calculator just to see what would come up, because usually that can be used for percentage, and when your doing the simp interest formula. I got 266
That's wrong.

we said Simple Interest = Principal * Rate * Time

the money owed would be $23400 So, Simple Interest = 23400 * 0.08 * 5 =$9360

I said 60 months, but i think the simple interest is per year. (besides, when i use 60 months i get a huge amount that can't be right)

12. I'm still waiting on your response to the last question