GRADE 7
Mathematics : Social Arithmetics
Feb 09, 2023
22. Anna borrows money from a friend at 10% (per year) simple interest rate to do business. She
must repay the loan in 6 months, with monthly payment of $35. Calculate:
a. the amount of money she paid to her friend after 6 months
b. the amount of money she borrowed
23. A man buys a dozen cameras for $1800. He sell them at a profit of $36 each. find his profit
percentage.
24. Simon ordered 200 boxes of Fuji apples from China. He paid $28 per box for the apples. There
were 60 fruits in each box and he expected 15% of them to spoil. If he wants to make a profit of
80%, what should be the selling price per fruit?
25. A shopkeeper buys 300 identical articles at a total cost of $1500. He fixes the selling price of each
article at 20% profit and sells 260 articles at this price. As for the remaining articles, he sells them
at 50% of the selling price. Calculate the shopkeeper ‘s total profit.
26. A finance charges $55 simple interest on a sum of money which is borrowed for five months.
Given that the rate of interest is 12% per year, find the sum of money borrowed.
27. A bank charges 2% per month simple interest on personal loans. If John borrows $6400 for a
period of 2 years and 1 month, find:
a. total interest he has to pay.
b. total money he needs to pay to bank.
c. If he wants to pay in instalment (cicilan), calculate the money he needs to pay every month.
28. Andrew lent Roger $4800 for 7 months. At the end of this period Roger had to pay Andrew an
interest of $119. What was the rate of simple interest per year?
4
GRADE 7
Mathematics : Social Arithmetics
Feb 09, 2023
29. Peter buys a window air-conditioner at $900. He pays 20% deposit (uang muka) and the rest will
be paid in installment in 48 months. Interest on the balance is charged at 10%. Find:
a. the cost of his monthly instalment.
b. the amount he saves by paying the air-con in cash.
30. The profit made on a certain laptop is 30% of the cost price. If the profit is $270, find:
a. the cost price
b. the selling price of the laptop.
31. A man bought 400 dozen pencils at $0.80 a dozen. He sold half of them at $1.05 a dozen and the
rest at $0.75 a dozen. Find his profit percentage.
32. In what time will $400 amount to $512 if the simple interest is the calculated at 14% p.a.(per
year)?
33. A sum amount to $2400 at 15% simple interest per annum after 4 years. Find the sum.
34. Kelsey takes out a 30-months period of loan for to start a business after high school. The bank
charges her 8% interest per year for the loan, and she need to pay $240 every month. Calculate:
a. the total money that Kelsey would pay to the bank
b. the loan that the bank give to her.
35. A cell phone was marked at 40% above the cost price and a discount of 30% was given on its
marked price. Find the gain or loss percent made by the shopkeeper.
36. During a 2-2 sale date, a Shopee seller gives double discount of 20% + 20%, so the costumers
only need to pay Rp. 7,680,000 for a TV product. Find the original normal price of the TV.
5