Question

When the cost of cigarettes increases by 25 %, a man reduces his annual consumption by 10 %. Find the % change in his annual expenditure on cigarettes?

Answer 1

Step-by-step explanation:

For this

let this person consume 20 cigarettes per anum at 20 rs per cigarette

so the expenditure was

20×20=400

now rate is increased by 25% so the new rate is

20×125/100 = 25

and expenditure is reduced by 10%

20×90/100=18

new expenditure is

25×18=450

difference is 450 - 400 = 50

% change is

50×100/400= 12.5%

answer

Answer 2

Answer:

12.5% change in his annual expenditure om cigarettes.

Step-by-step explanation:

In this question,

Cost of a cigarettes increases by 25%, a man reduces his annual consumption by 10%.

We need to find the %change in his annual expenditure on cigarettes?

For this

Let the person consume 30 cigarettes per annum at 30 Rs. per cigarette

So the total expenditure was

30 × 30 = 900

Now rate is increased by 25% so the new rate is

$30\times \frac{125}{100}\  =\ 37.5 Rs.$

Now, man reduces his annual consumption by 10%.

$30\times\frac{90}{100}\ =\ 27$

New expenditure is

37.5 × 27 = 1012.5

Difference between initial expenditure and final expenditure  

1012.5 - 900 = 112.5

% change is

$112.5\times \frac{100}{900}\ =\ 12.5\%$

Therefore, 12.5% change in his annual expenditure om cigarettes.