General Mathematics

Question: If the price of sugar rises from Rs `6` per kg to Rs `7. 50 per kg, a person, to have no increase in his expenditure on sugar, will have to reduce his consumption of sugar by :
A
`15%`

B
`20%`

C
`25%`

D
`30%`

Note: Let original consumption `= 100 kg &` new consumption `= x kg` `:. 100 xx 6 = x xx 7.50 => x = 80 kg.` :. Reduction in consumption`= 20%`
1. Report
Question: The price of sugar increase by `32%`. A family reduces its consumption so that the expenditure of the sugar is up by `10%` only. If the total consumption of sugar before rise was `10` kg per month, then the consumption of sugar per month at present (in kg) is :
A
`8 1/3`

B
`8 1/2`

C
`8 3/4`

D
`9`

Note: Let original rate `= Rs. x∕kg.` Consumption `= 10 kg.` Expenditure`= Rs. 10x.` New expenditure `= 110% of Rs. 10x = 11x.` New rate`= 132% of x = (33x)/25.` New consumption `= (Expenditure/Rate)` `= (11x xx 25/(33x)` `= (25)/(3) kg.` `= 8 1/3 kg.`
1. Report
Question: Prices register an increase of `10%` on food grains and `15%` on other items of expenditure. If the ratio of an employee's expenditure on food grains and other items be `2 : 5`, by how much should his salary be increased in order that he may maintain the same level of consumption as before, his present salary being `Rs. 2590 ?`
A
`Rs. 323.75`

B
`Rs. 350`

C
`Rs. 360.50`

D
None

Note: Let expenditure on food grains and other items be Rs. 2x and Rs. 5x. `2x + 5x = 2590` `or x = 370.` `:. F = 2 xx 370` `= 740, 0 = 5 xx 370` `= 1850.` New expenditure `= 110% of 740 + 115% of 1850.` `= (110/100 xx 740 + 115/100 xx 1850)` `= Rs. (814 + 2127.50)` `= Rs. 2941.50.`
1. Report
Question: The population of a town increases by `15%` annually. If its population was `8000` in `1995`, what will it be in `1997` ?
A
`9200`

B
`10400`

C
`9600`

D
`10580`

Note: Population in `1997 = 8000 xx (1 + (15)/(100))^2` `= (8000 xx (23)/(20) xx (23)/(20))` `= 10580`.
1. Report
Question: The population of a town is `18000`. It increases by `10%` during first year and by `20%` during the second year. The population after `2` years will be :
A
`19800`

B
`21600`

C
`23760`

D
None

Note: Required population `= 18000 xx (1 + (10)/(100)) xx (1 + (20)/(100))` `= (18000 xx (11)/(10) xx 6/5)` `= 23760`.
1. Report
Question: The value of a sewing machine depreciates every year by `4%`. Its value at present is `Rs 200`. What will be its value after `2` years ?
A
`Rs. (200 xx (23)/5)`

B
`Rs. [(200 xx (24)/(25))^2]`

C
`Rs. [200 xx ((25)/(26))^2]`

D
`Rs. [(200 xx (26)/(25))^2]`

Note: value after `2` years `= Rs. [200 xx (1 - 4/(100))^2]` `= Rs. [200 xx ((24)/(25))^2]`
1. Report
Question: The population of a city increases at the rate of `5%` annually. Its present population is `1,85,220`. Its population `3` years ago was :
A
`181500`

B
`183433`

C
`160000`

D
`127783`

Note: Population `3` years ago `= (185220)/(1 + (5/(100))^3` `= (185220 xx (20)/(21) xx (20)/(21) xx (20)/(21))` `=160000`.
1. Report
Question: The value of a machine depreciates at the rate of `10%` every year. It was purchased `3` years ago. If its present value is `Rs. 8748`, its purchase price was :
A
`Rs. 10000`

B
`Rs. 11372.40`

C
`Rs. 12000`

D
None

Note: `P xx (1 - (10)/(100))^3 = 8748` `=> P = (8748 xx (10)/9 xx (10)/9 xx (10)/9)` `= Rs. 12000`.
1. Report
Question: A ball pen factory decided to reduce its production by `10%` over that of previous month for next `3` months starting from February `1994`. In January `1994`, it produced `3000` ball pens. How many ball pens were produced in March `1994` ?
A
`2700`

B
`2430`

C
`2187`

D
`2400`

Note: Required number `= 3000 xx (1 - (10)/(100))^2` `= 3000 xx 9/(10) xx 9/(10)` `= 2430`.
1. Report
Question: The present population of a country estimated to be `10` crores is expected to increase to `13.31` crores during the next three years. The uniform rate of growth is :
A
`8%`

B
`12.7%`

C
`10%`

D
`15%`

Note: `10 "crores" xx (1 + R/(100))^3` `= 13.31 "crores"`. `:. (1 + R/(100))^3` `= (13.31 "crores")/(10 "crores")` `= (13.31)/(10)` `= (1331)/(1000)` `= ((11)/(10))^3`. So, `(1 + R/(100))` `= (11)/(10)` or `= R/(100)` `=((11)/(10) - 1)` `= 1/(10)` or `R = 10`.
1. Report

First Prev 99 100 101 102 103 Next Last

Question: If the price of sugar rises from Rs `6` per kg to Rs `7. 50 per kg, a person, to have no increase in his expenditure on sugar, will have to reduce his consumption of sugar by :

Question: The price of sugar increase by `32%`. A family reduces its consumption so that the expenditure of the sugar is up by `10%` only. If the total consumption of sugar before rise was `10` kg per month, then the consumption of sugar per month at present (in kg) is :

Question: The population of a town increases by `15%` annually. If its population was `8000` in `1995`, what will it be in `1997` ?

Question: The population of a town is `18000`. It increases by `10%` during first year and by `20%` during the second year. The population after `2` years will be :

Question: The value of a sewing machine depreciates every year by `4%`. Its value at present is `Rs 200`. What will be its value after `2` years ?

Question: The population of a city increases at the rate of `5%` annually. Its present population is `1,85,220`. Its population `3` years ago was :

Question: The value of a machine depreciates at the rate of `10%` every year. It was purchased `3` years ago. If its present value is `Rs. 8748`, its purchase price was :

Question: A ball pen factory decided to reduce its production by `10%` over that of previous month for next `3` months starting from February `1994`. In January `1994`, it produced `3000` ball pens. How many ball pens were produced in March `1994` ?

Question: The present population of a country estimated to be `10` crores is expected to increase to `13.31` crores during the next three years. The uniform rate of growth is :