Use percentage questions to calculate parts, increases, decreases, original values and compound changes in money or measurement contexts.
The area of land on a farm is 120 hectares.
The farmer grows crops on 87 of the land.
On 32 of the land used to grow crops, the farmer grows wheat.
Last year, the farmer made 31500 euros from selling his wheat.
His total income was 42000 euros.
Write 31500 as a percentage of 42000
Final answer:
Write 23% as a decimal.
Rita has some beads in a bag.
Of these beads, Rita gives
Rita now has 3 beads left in the bag.
0.23
1
Work out 45% of 800
0.45×800=360
Equivalent methods include:
10045×800or100800×45
Final answer:
360
A1.
Otis sells ice creams.
On Friday, Otis sells 75 ice creams.
On Saturday, Otis sells 87 ice creams.
Work out the percentage increase in the number of ice creams Otis sells from Friday to Saturday.
Claudia buys an ice cream machine for 960 Swiss francs.
The value of the ice cream machine depreciates by 20% each year.
Working:
87-75=127512×100=16
Final answer:
16%
M1 for the increase or ratio. M1 for a correct percentage increase method. A1 for 16.
Teresa invests $ 2000 for 3 years in a savings account. She gets 4% each year compound interest.
Sam invested $T.
The value of his investment decreased by 9% each year.
At the end of the first year, the value of Sam's investment was $1365.
Work out the value of T.
1365÷(1−0.09)=1365÷0.91T=1500
Marking guidance:
- M2 for a complete method
- M1 for equivalent setup such as 91%=1365, (1-0.09)T=1365, or T-0.09T=1365
- A1 for 1500
Otis sells ice creams.
On Friday, Otis sells 75 ice creams.
On Saturday, Otis sells 87 ice creams.
Work out the value of the ice cream machine at the end of 3 years.
Working:
960×0.83=491.52
Final answer:
491.52
M1 for a first depreciation step such as 0.8×960=768. M1 for a complete 3-year depreciation method. A1 for 491.52;
accept 491-492. Special-case marks as in official notes.