CLASS VIII

PROFIT , LOSS and DISCOUNT

1) Find selling price if
a) Marked price = Rs 1300 and Discount = 1.5%
b) Marked price = Rs 5450 and Discount = 5%

2) Fiind marked price if
a) Selling price =Rs 3430 and discount = 2%
b) Selling price =Rs9250 and discount = 7 ½ %

3) Find Discount per cent when
a) M.P = Rs 625 and S.P = Rs 562.50
s) M.P = Rs 1600 and S.P =Rs1180

4) S.P of 9 articles is equal to the C.P of 15 articles.Find the gain or loss per cent in the transaction.

5) The C.P of an article is Rs 360.If after allowing a discount of 10% , the shopkeeper still earns 25%
profit , find the M.P of the article.

6) A shopkeeper purchases a TV for Rs 2000 and a radio for Rs 750.He sells the TV at a profit of 20%
and radio at a loss of 5%.What is his total loss or gain.

7) The M.P of an article is Rs 500.The shopkeeper gives a discount of 5% and still makes a profit
of 25%.Find the cost price of the article.

8) A person gained 20% after selling an article for Rs 240.At what price should he sell the article to
gain 10%.

9) Harish bought a cradle for Rs 215 and later sold it to Ram at a profit of 5%.He used it for his son for
2 years and then sold it to his servant at a loss of 20%.For how much did the servant get it.

10) A shopkeeper buys pens at the rate of Rs 75 per 100.For much should he sell each pen so as to make a gain of 15%.

11) By selling a pen for Rs 17.50, a shopkeeper suffers a loss of 12 ½ %.What price of the pen would bring the shopkeeper a gain of 20%.

12) By selling an article for Rs 24 , A person loses 20% of his cost.If he sells it for Rs 27 ,what profit or loss would be there for him.

14) A dealer buys an article for Rs 380.At what price must he mark itr so that after allowing a discount of 5% he still makes a profit of 25%.

15) The C.P of 100 mangoes is equal to the S.P of 15 mangoes.Find the gain or loss %.

Studying Mathematics

Studying Mathematics is Different from Studying Other Subjects

• Mathematics is learned by doing problems. Do the homework. The problems help you learn the formulas and techniques you do need to know, as well as improve your problem-solving power.
• 
  A word of warning: Each class builds on the previous ones, all semester long. You must keep up with the Instructor: attend class, read the text and do homework every day. Falling a day behind puts you at a disadvantage. Falling a week behind puts you in deep trouble.
• 
  A word of encouragement: Each class builds on the previous ones, all semester long. You're always reviewing previous material as you do new material. Many of the ideas hang together. Identifying and learning the key concepts means you don't have to memorize as much.
• 
  The higher the math class, the more types of problems: in earlier classes, problems often required just one step to find a solution. Increasingly, you will tackle problems which require several steps to solve them. Break these problems down into smaller pieces and solve each piece - divide and conquer!
• 
  When you work problems on homework, write out complete solutions, as if you were taking a test. Don't just scratch out a few lines and check the answer in the back of the book. If your answer is not right, rework the problem; don't just do some mental gymnastics to convince yourself that you could get the correct answer. If you can't get the answer, get help.
• 
  The practice you get doing homework and reviewing will make test problems easier to tackle.

Solving an Applied Problem

First convert the problem into mathematics. This step is (usually) the most challenging part of an applied problem. If possible, start by drawing a picture. Label it with all the quantities mentioned in the problem. If a quantity in the problem is not a fixed number, name it by a variable. Identify the goal of the problem. Then complete the conversion of the problem into math, i.e., find equations which describe relationships among the variables, and describe the goal of the problem mathematically.

Solve the mathematics problem you have generated, using whatever skills and techniques you need .
As a final step, you should convert the answer of your mathematics problem back into words, so that you have now solved the original applied problem.

Good Test Taking Strategy

Just as it is important to think about how you spend your study time , it is important to think about what strategies you will use when you take a test. Good test-taking strategy can make a big difference to your grade!

Taking a Test

First look over the entire test. You'll get a sense of its length. Try to identify those problems you definitely know how to do right away, and those you expect to have to think about.

Do the problems in the order that suits you! Start with the problems that you know for sure you can do. This builds confidence and means you don't miss any sure points just because you run out of time. Then try the problems you think you can figure out; then finally try the ones you are least sure about.

Time is of the essence - work as quickly and continuously as you can while still writing legibly and showing all your work. If you get stuck on a problem, move on to another one - you can come back later.

Work by the clock. On a 50 minute, 100 point test, you have about 5 minutes for a 10 point question. Starting with the easy questions will probably put you ahead of the clock. When you work on a harder problem, spend the allotted time (e.g., 5 minutes) on that question, and if you have not almost finished it, go on to another problem. Do not spend 20 minutes on a problem which will yield few or no points when there are other problems still to try.

Show all your work: make it as easy as possible for the Instructor to see how much you do know. Try to write a well-reasoned solution. If your answer is incorrect, the Instructor will assign partial credit based on the work you show.

Never waste time erasing! Just draw a line through the work you want ignored and move on.
Not only does erasing waste precious time, but you may discover later that you erased something useful (and/or maybe worth partial credit if you cannot complete the problem).
You are (usually) not required to fit your answer in the space provided - you can put your answer on another sheet to avoid needing to erase.

Make sure you read the questions carefully, and do all parts of each problem.

Verify your answers - does each answer make sense given the context of the problem?
If you finish early, check every problem (that means rework everything from scratch).

CLASS - 8

COMPOUND INTEREST

1) Find the compound interest on Rs 64000 at 2.5 p.a. for 3 years, interest being compounded annually.

2) Simple interest on certain sum at certain rate for 2 years is Rs 200. If the interest is compounded annually, the compound interest is Rs 210. Find the rate and sum.

3) Find the sum for which the difference between the simple interest and compound interest for 2 years at 4% per annum is Rs 20.

4) Simple interest on a sum of money for 3 years at 6 ¼ % p.a.is Rs 2400.What will be the compound interest on that sum at the same rate for the same period.

5) A certain sum amounts to Rs 5832 in 2 years at 8% compound interest. Find the sum.

6) The difference between the simple interest and compound interest on a certain sum for 2 years at 7.5% per annum is Rs 360.Find the sum.

7) At what rate per cent will a sum of Rs 1000 amount to Rs 1102.50 in 2 years at compound interest.

8) The compound interest on Rs 1899 at 10% per annum, for a certain period of time is Rs.378.Find the time in years.

9) Rekha invested a bum of Rs 12000 at 5% per annum compound interest. She received a sum of Rs 13230 after ‘n’ years. Find ‘n’.

10) I borrow Rs 12000 from Neelam at 6% p.a. simple interest for 2 years. Had I borrowed this sum at 6% p.a. compound interest, what excess amount would I have to pay him.

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