Question: The smallest fraction whivh should be subtracted from the sum of
`1 3/4, 2 1/2, 5 7/12, 3 1/3` and `2 1/4` to make the result a whole number is .
A
`5/12`
B
`7/12`
C
`1/2`
D
`7`
Note: Sum of given numbers ,
`= 7/4 + 5/2 + 67/12 + 10/3 + 9/4`
`= ((21 + 30 + 67 + 40 + 27)/12)`
`= 185/12`.
The whole number just less than `185/12` is `15`.
Let` 185/12 - x = 15`.
Then, `x = (185/12 - 15)`
`= 5/12`.
Question: on sports day ,if `30` children were made to stand in a colum ,`16` colums could be formed .If `24`chidren were made to stand in a colum,how many colums could be formed ?
A
`45`
B
`20`
C
`22`
D
`29`
Note: The number of children
`= (30 xx 16)`
= 480`
Number of columns of `24` children each
`= (480/24)`
`= 20`
Question: A third of vinod ,s marks in Mathmatices exceeds a half of his marks in socail Studies by `30`.If he got `240`marks in the two subjects together, how many marks did he get in social Studies ?
A
`40`
B
`60`
C
`80`
D
`None of these
Note: `1/3 M - 1/2 s = 30,`
`s + M = 240`
:. 3S - 2M = 180`,
`S + M = 240`
on solving, we get :S = 132`.
Question: If`1/8` of a pencil is black, `1/2` of the remaining is white and the remaining `3 1/2` cm
is blue ,then the total lengh of pencil is :
A
`6 cm`
B
`7 cm`
C
`8 cm`
D
`11 cm`
Note: Let, total length `= x cm`.
Black part ` = x/8`.
Remaining `(x - x/8)`
`7x/8`.
White part `= 1/2 xx (7x)/8`
`= (7x)/16`
Remaining `= ((7x)/8 - (7x)/16)`
`(7x)/16`
:. `(7x)/16`
7/2`
or ` x = 16/2 `
`= b cm`.
Question: The number of students in each section of a school is `24`.After admitting new student,three new sections were started. Now the total number of section is `16`and there are 21 students in each section.The number is new students admitted is ;
A
`24`
B
`14`
C
`48`
D
``114`
Note: Original number of section
`= (16 - 3) = 13`
Original number of student
`= (24 xx 13) = 312`.
Present number of students
`= (21 xx 16) = 336`.
Number of new students admitted
`= (336 - 312) = 24`
Question: In a garden ,there are `10` rows and `12` columns of mango trees .The distance between two trees is `2`metres and a distance of one metre is left from all sides of the boundary of the garden. The lengh of the garden is .
A
`20 m`
B
`22 m`
C
`24 m`
D
`26 m`
Note: Each row contains `12` plants. ,Leaving `2` corner plants ,`10` plans in between have `(10 xx 2) metres & `1` metre on each side is left .
:.Length `= (20 + 2) m = 22 m.
Question: In a school `1/6`th of the girls and `1/7`of the boys took part in N.C.C camp .What fraction of the total number of students in the college took part in the camp ?
A
`13/40`
B
`13/80`
C
`2/13`
D
Data inadequate
Note: Out of girls ,`1` took part in n.C.C
Out of `7` boys ,`1` took part in N.C.C
:. Out of `13` students ,`2` took part in N.C.C
:.`1/13` of the total number took part in N.C.C
Question: One third of the boys and one half of the girls of a college participate in a socail work project. If the number of participarting students is `300` out of which `100` are boys ,what is the total number of students in the college ?
A
`500`
B
`600`
C
`700`
D
`800`
Note: Number of boys who participate `= 100`.
`:. 1/3` of boys `= 100` or total number of boys `= 300`.
Number of girls who participate `= 200`
``1/2` of girls `= 200` or total number of girls `= 400`
`:. total number of students `= (300 + 400)`
`= 700`
Question: In an office ,`3/4` of the can niether type nor take shorthand .However `1/5th can type and `1/3` rd can take shorthand .What part of the whole staff can do both ?
A
`1/5`
B
`3/40`
C
`13/40`
D
`17/60`
Note: Let total number be x,
Then,the number who can type or take short hand
`= (x - (3x)/4)`
`= x/4`.
Let A = set of person who can type & B = set of person who can take short hand .
`:. n (A∪B) =x/4,n(A)`
`= x/5 & n (B) = x/3`.
`Now n(A∩B) = n(A) + n (A∪B)`
`= (x/5 + x/3 - x/4)`
`= ((12x + 20x - 15x)/60)`
`= 17x/60`
`= 17/60`of the whole .