Mathematics for IGCSE & O level - Percentages (Section 6)
1
What is the formula for compound interest?
Risposta
(A)
A = P(1 + r/100)^n
2
Due to inflation, prices increase by 5% per year. An item costs $12 now. What will it cost in 2 years' time?
Risposta
(B)
$13.23
3
What percentage is 150 of 200?
Risposta
(B)
75%
4
What is the definition of inflation?
Risposta
(B)
An increase in the general level of prices
5
What is 2.4% of 5000?
Risposta
(B)
120
6
Andrew invested $3500 in a six-year bond that paid 5% compound interest for the first three years and 7.5% compound interest for the next three years. What is the amount in the bond, to the nearest cent after six years?
Risposta
(B)
$4907.97
7
Andrew invested $3500 in a six-year bond that paid 5% compound interest for the first three years and 7.5% compound interest for the next three years. What is the amount in the bond, to the nearest cent after three years?
Risposta
(B)
$4043.63
8
A trader buys an item for $12.50 and sells it at a loss for $5. What is his percentage loss?
Risposta
(C)
64%
9
Selena invests $4000 and receives 5% interest a year which is added to the amount each year. What is her investment worth in total after 6 years?
Risposta
(B)
$5360.38
10
Decrease $500 by each of these percentages:
a) 5%
b) 10%
Risposta
(B)
$475, $450
11
A shop increases prices by 5% and then by another 5%. What is the overall percentage increase (to nearest whole %)?
Risposta
(A)
9%
12
If the price of an item increases by 7% one year and then decreases by 7% the following year, what is the overall percentage change?
Risposta
(C)
-0.49%
13
Pulova has high inflation. A car cost 78000 dubs (their unit of currency) in January 2023. In January 2024? Prices increased by 15% a month for the first six months and 12.5% for the next six months in 2023. What will it cost in January 2024?
Risposta
(C)
$199300
14
Increase $400 by each of these percentages:
a) 1%
b) 5%
Risposta
(A)
$404, $420
15
Which of these is equivalent to 0.75 as a percentage?
Risposta
(B)
75%
16
A shopkeeper buys an article for $22 and sells it for $27. What is his percentage profit?
Risposta
(D)
22.5%
17
What does the 'P' represent in the compound interest formula?
Risposta
(A)
Principal
18
Françoise buys a car for $9500 and sells it a year later for $8300. What is her percentage loss?
Risposta
(A)
12.6%
19
A shop increases the price by 9%.
What is the sale price of a article previously was $300
Risposta
(A)
327
20
In a class of 25 students, 10 are girls. What percentage are girls?
Risposta
(C)
40%
21
If a car costs 78000 dubs in January 2023, and prices increase by 15% per month, what does it cost after one month?
Risposta
(A)
89700
22
Mr. Costa was given an 8% pay rise every year. His starting salary was $28,500. How much does he earn after four rises?
Risposta
(B)
$38786.20
23
A shopkeeper buys an article for $10 and sells it for $12.
What percentage profit does the maker make?
Risposta
(B)
20%
24
What is the multiplier used to increase a quantity by 7%?
Risposta
(A)
1.07
25
What is the multiplier to decrease by 15%?
Risposta
(B)
0.85
26
A shopkeeper buys potatoes at $1.40 per kilogram and sells them for $1.80 per kilogram. What is his percentage profit?
Risposta
(A)
28.6%
27
How do you calculate the loss percentage?
Risposta
(D)
(Cost Price - Selling Price) / Cost Price * 100
28
What is 10% of $6.80?
Risposta
(A)
$0.68
29
What is the simple interest of $1000 at 5% for 2 years?
Risposta
(B)
$100
30
Find 50% of $680.
Risposta
(A)
$340
31
What is the multiplier when increasing by 10%
Risposta
(B)
1.1
32
What is 0.5% of $8.60?
Risposta
(D)
$0.043
33
Which statements about Jerry's annual salary of $48000 are correct?
(a) Jerry's monthly gross pay = $4000. (b) If Jerry's commission for the sales = $7500, then in May he will receive $5750. (c) Total pay for May = $5750.
Risposta
A
B
34
What information is needed to find the value of an investment after a certain time, when using the compound interest formula?
Risposta
A
B
C
35
What is the value of the investment after four years if $1500 is invested in an account that earns compound interest of 4% annually?
Risposta
(A)
$1747.34
36
Steve's wage is $195 per week. How much does he earn in a year?
Risposta
(C)
$9,360
37
Salim has $4000 to invest for 5 years. He has two options: 3.5% simple interest or 3.25% compound interest. Which is the better option?
Risposta
(A)
3.5% simple interest
38
What term is given to the original amount of money invested?
Risposta
(A)
Principal
39
How do you calculate the profit percentage?
Risposta
(C)
(Selling Price - Cost Price) / Cost Price * 100
40
Express 10 in a percentage of 100.
Risposta
(B)
10%
41
What is 2.5% of $400?
Risposta
(A)
$10
42
Find the original quantity if a quantity is decreased by 5% and it is now $90.
Risposta
(A)
$94.74
43
If an item increases in value by 10% one year and then decreases by 10% the next year, what is the final change as a percentage?
Risposta
(C)
-1%
44
Express 4 as a percentage of 5.
Risposta
(D)
80%
45
What is 5% of $100?
Risposta
(B)
$5
46
A shop increases the price by 9%.
What is the sale price of a article previously was $300?
Risposta
(C)
$327
47
What will be the value of Martin's shares after 10 years if he had shares worth $8000 and they increased in value by 7.5% each year?
Risposta
(D)
$16197
48
Which type of interest is added to the original amount each year?
Risposta
(B)
Compound Interest
49
What does the 'A' represent in the compound interest formula, A = P(1 + r/100)^n?
Risposta
(C)
Final Amount
50
A pair of shoes are marked down by 15%. If the original price was $80, what is the sale price?
