Question

5. From 2010 to 2011, the sales of watch decreased by 80%. If the sales in 2012 was the same as in 2010, then what per cent did it increase from 2011 to 2012 ? ​

Answer 1

$Let \: Sale \: in \: 2010 \: =100$

$let \: sale \: in \: \: 2011 = \: 80$

$Required \: Increase \: = \frac{100 - 20}{20} \times 100$

$= \frac{80}{20} \times 100$

$= \frac{8000}{20}$

$= 400\%$

Answer 2

Step-by-step explanation:

LetSalein2010=100

let \: sale \: in \: \: 2011 = \: 80letsalein2011=80

Required \: Increase \: = \frac{100 - 20}{20} \times 100RequiredIncrease=

20

100−20

×100

= \frac{80}{20} \times 100=

20

80

×100

= \frac{8000}{20}=

20

8000

= 400\%=400%