141. A person saves 8% of his income. Two years later, his income shoots up by 20% but his saving remain the same. Find the hike in his expenditure.
Sol:-
∴ Hike in expenditure = \(\frac{{112 – 92}}{{92}} \times 100\)
= \( \boldsymbol{21\frac{{17}}{{23}}\%} \)Â Â Â Â Answerf
142. A is 60% more than B, C is \( \boldsymbol{\frac{3}{4}} \) of A and D is 50% more than C. Now, each of A, B, C and D is increased by 10%. Find what percent of A is D(after the increase).
Sol:
∴ Required % value = \(\frac{{198}}{{176}} \times 100\)
=Â 112.5%Â Â Â Â Â Answer
143. Ankit has Rs. A and his friend Bharat has Rs. B. Ankit spends 15% of his money and Bharat also spends the same amount as Ankit did. What percentage of his money did Bharat spend ?
Sol:
Let Bharat spends x% of his moneyÂ
B × x% = A × 15%
∴ x = \( \boldsymbol{\frac{{15A}}{B}} \)   Answer
144. A and B have Rs. 1600. A spends 125 of his money while B spends 20% of his money. They are left with a sum that constitutes 85% of the whole sum. Find what amount is left with B.
Sol:
They are left with 85% of the whole sum. It means they spent 15% of the whole sum.
amount of B = \(\frac{3}{{3 + 5}} \times 1600 = 600\) Rs.
After spending 20% of his money, amount left with B = 600 × 80% = 480 Rs.   Answer
145. In order to maximise his gain, a theatre owner decides to reduce the price of tickets by 10% and as a result of this, the sale of tickets increases by 30%. If as a resutl of these changes, he is able to increase his weekly collection by Rs. 1820000 Rs., find by what value did the grass collection increases per day.
Sol:
weekly increase = 1820000
∴ Gross collection increase per day = \(\frac{{1820000}}{7}\) = 260000   Answer
146. The cost of food accounted for 25% of income of a family. If the income gets raised by 20% then what should be the percentage decrease in the food expenditure as a percentage of the total income to keep the food expenditure unchanged between the two years.
Sol:
Let the income of the family = 100 Rs.
∴ expenditure on food = 100 × \(\frac{{25}}{{100}}\) = 25 Rs.
After increase of 20% income = 100 × \(\frac{{120}}{{100}}\) = 120 Rs.
According to question,Â
Expenditure is same in both cases.
∴ % expenditure = \(\frac{{25}}{{120}}\) × 100 = 20.833%
∴ % decrease in expenditure = 25 – 20.833
=Â 4.16%Â Â Â Answer
147. Ankit goes to a shop to buy a T.V. costing Rs. 14170. The rate of sales tax is 9%. He tells the shopkeeper to reduce the price of T.V. to such an extent that he has to pay Rs. 15000 inclusive of sales tax. Find the % reduction needed in the price of T.V. to just satisfy his requirements.
Sol:
Let reduced price of T.V. = 100x
∴ 100x + 100x × 9% = 14170
109x = 14170
x = 130
∴ reduced price of T.V. = 130×100 = 13000
∴ % reduction = \(\frac{{14170 – 13000}}{{14170}} \times 100\)
=Â 8.26%Â Â Â Â Â Â Â Â Answer
148. A man donated 50% of his wealth to his first son, 50% of t he remaining to his second son, 50% of the remaining to his third son. If their combined share is 135100 Rs. Then find the initial wealth of the man.
Sol:
∴ initial wealth = 8 × 19300 = 154400      Answer
149. The population of a city increases with a uniform rate of 8% per annum, but due to immigration there is a further increase of population by 1% (However, this 1% increase in population is to be calculated on the population after the 8% increase and not on the preavious years population). Find what will be the percentage increase in population after 2 years.
Sol:
Let population at the start = 100
∴ population after 2 years = 100 × 1.08 × 1.01 × 1.08 × 1.01
= 118.984
∴ required % ↑ = 18.984%      Answer
150. The ratio of saving to expenditure for the month of january was 2:13. In the month of february due to unforseen expenditure, saving fell to 50% of the amount saved last month. Salary for the month of january was Rs. 10000. In the month of february there was increase of 15% in the salary. What was the expenditure in the month of february.
Sol: