Finished: Math Practice Questions Air Class

1. A ​shop bought 80 laptops at $4000 each. It then sold 50 of them at a 20% profit in
the first month. In the second month, the remaining laptops were sold at 75% of the
first month's selling price. How much profit was made altogether?

Steps: 20 percent of 4000 is 800 so they sold the laptops for 4800

4800 take away the cost of 4000

800 x 50

40000

75 percent of 4800 is 3600

take away the cost of 4000

-400

-400 times the 30 computers

-12000

adding up the 40000 and -12000

28000

Answer: 28000

2 ​A product was marked at 20% above the cost price. It was eventually sold at 80%
of the selling price. The loss was $40. What was the cost price of the product?

Steps:

Cost=C

Marked price = MP

Loss=L

Selling price=SP

MP=120%* C

SP=80%*MP

L=40

C-SP=40

C-80%MP=40

C- 0.96C =40

0.04C=40

0.01C=10

C=1000

Answer: C=1000

3 Two different brands of television sets were sold at the same price of $2040 each . The sale of the first set made a profit of 20% while that of the second set made a loss of 20%. Did the shop owner profit from the sales of the two television sets?

no the shop keeper earned $408 and then lost $408 dollars.

The shopkeeper did not profit; the net result was zero.

4 ​Stephen puts $800 in a bank that earns him a simple interest of 8% per annum. What is the amount of simple interest earned in 3 years? When will his interest accumulate to $512?

Steps:

every year he will earn 64 dollars.

512/64=8

3 x 64 = 192

Answer: after 3 years of simple interest he will earn $192 and it will take him 8 years to earn 512 dollars of interest.

5 ​Maurice deposits $500 with the bank. The interest rate is calculated at 3% on a
yearly basis. How much will she get at the end of 2 years?

Steps:

3% of 500 is 15

now she has 515 dollars in her account.

now she has 530.45 dollars in her account

Answer: $530.45