Question

A man spends 80% of his earnings his earnings increased by 25% andhis expenses increased by 20% by what percent his savings increase

Answer 1

let 100n be his salary
he spents 80n,saves 20n
after 25% increase in salary, salary=125n
after 20% increase in expenses,expenses=80n+80n*20/100=80n+16n=96n
so his savings =125-96=29n
increase in savings=(29-20)/20=9/20=45%

Answer 2

Answer:

Percent his savings increase is 45%.

Step-by-step explanation:

Given : A man spends 80% of his earnings his earnings increased by 25% and his expenses increased by 20%.

To find : By what percent his savings increase?

Solution :

Let his earnings or income be x

Let his expenditure be y

and his savings be z

So, we have

x=y+z

Let income x be 100,

Then y = 80% of x and rest 20% will be z

So, y= 80, and z= 20

Now, his income increases by 25%,

x(new) = x + 0.25x = 1.25x = 125

and Expenditure also increases by 20%,

y(new) = y + 0.2y = 1.2y = 1.2 × 80 = 96

So, we put values

x(new) = y(new) + z(new)

125 = 96 + z(new)

z(new) = 29

Increase in z will be = z(new) - z= 29 - 20 = 9

Percentage increase in $z = \frac{9}{20}\times 100= 45\%$

Therefore, Percent his savings increase is 45%.