Finished: Math Practice Questions Air Class 2

1. Profit and Loss on Mobile Phones

A store purchased 120 mobile phones at $300 each. It sold 80 of them at a 25% profit in the first month. The remaining phones were sold in the second month at 60% of the first month's selling price. What was the total profit made?
Steps:

25 percent of 300 is 75 so the store sold the phones for 375

in the first month they earned 30000 and spent 24000

so in the first month they earned 6000

in the second month they sold it for 60 percent of 375 which is 225

they sold 40 phones so 40 X 225 which is 9000

in the seconds month they earned 9000 but spent 12000

so they lost 3000

adding these together

they earned 3000


Answer: 3000


2. Loss Due to Discounted Selling Price

A watch was marked 30% above the cost price but was sold at 70% of the marked price, resulting in a loss of $45. What was the cost price of the watch?
Steps:

  • Let CP = x.
  • MP = 1.3x.
  • SP = 0.7 * MP = 0.91x.
  • Loss = CP - SP = x - 0.91x = 0.09x = 45 → x = 500.


Answer: x = 500.


3. Profit and Loss on Two Items

Two bicycles were sold for $1500 each. The first bicycle was sold at a 25% profit, while the second was sold at a 25% loss. Did the seller make an overall profit or loss?
Steps:

(CP1 = 1500/1.25 = 1200, CP2 = 1500/0.75 = 2000). Total CP = 3200, Total SP = 3000, so there's a loss of 200.


Answer: he loses 200


4. Simple Interest Calculation

David invests 1200 in a bank that offers a simple interest rate of 5% how much simple interest will he earn in 5 years.
Steps:

5 percent of 1200 is 60

so 60 times 5

300
Answer: 300


  1. Algebra

A cricket promised to return 2n kg of barley for every n kg of barley borrowed at the end of the first year. This meant that the interest rate was 100%. The greedy ant changed its mind and requested for the repayment with a simple interest every 4 months. Give an explanation for the change of mind.
Steps:

the ant realizes that if there is compound he will earn moor barley

compound interest will earn more because the money builds up!

Answer the ant will earn more barley so he asked to change to a compound four monthly payment