Percentages

Question 1

Increase £42 by 35%

Answer 1

42x1.35=£56.70

You want to find 35%. Add (add because increase) 35% to 100%=1.35

Question 2

Decrease £83 by 6.2%

Answer 2

83x0.938=£77.85

100% - 6.2% (take away because decrease) = 0.938%

Question 3

£6000 invested into a saving account that pays 4% per annum. How much will you have after 3 years?

Answer 3

Per annum = per year
(You can’t just work out 1 year x 3, because you have a different amount at the start of each year.

6,000 x 1.04^3
(1.04=%increase, ^3=years)
=6749.184
=6749.18

Question 4

Mark buys a motorbike for £6,000. If depreciates in value by 12.5% every year. How much is it worth after 7years?

Answer 4

(12.5% is of the new amount every year)
6000x0.875^7=2356.175423
=£2356.18

Question 5

£8000 is invested in an account that pays 6% every year the money is in he account. You receive the money (in interest) as a cheque at the very end. How much money in total would you have after 3 years?

Answer 5

£8000x0.06=£480
480x3=£1440
8000+1440=£4440

Question 6

A sale is on: 20% off everything. A TV is now worth £360. How much was it before the sale?

Answer 6

80% = £360
/divided by 8
10% = £45
(x10
100% = £450

Question 7

Matt receives a 35% pay rise and now earns £1620 per month. How much did he earn (per month) before the pay rise?

Answer 7

135% = £1620
/ divided by 135
1%=£12
/ x100
100%=1200

Question 8

Find 21 as a percentage of 35 (no calculator)

Answer 8

21/35
/divided by 7
3/5
/times by 20
60/100
= 60%

Question 9

Find 8nas a percentage of 23 (calculator allowed)

Answer 9

8/23 x 100 = 34.7826…
=34.8%
(You can have percentages as decimals)

Question 10

8.4(recurring)3567(recurring) is the same as what? (Give the number without the recurring)

Answer 10

8.435674356743567…

Question 11

What is the equation for percentage profit?

Answer 11

Percentage profit = (profit / original amount) x 100

Question 12

Tony bought a box of 24 oranges for £4. He sold all the oranges for 21p each, work out his percentage profit

Answer 12

24x21=504pence =£5.04
Profit = 5.04-4 =£1.04
%profit =1.04/4x100=26%

Question 13

What is the equation for percentage loss?

Answer 13

Percentage loss = loss / original amount x 100

Question 14

Mark buys a rare coin for £80 and sells it at a loss for £50. What is the percentage loss?

Answer 14

Loss = 80-50=£30

%loas =(30x80)x100=37.5%