Self Studies

Numerical Applications Test 17

Result Self Studies

Numerical Applications Test 17
  • Score

    -

    out of -
  • Rank

    -

    out of -
TIME Taken - -
Self Studies

SHARING IS CARING

If our Website helped you a little, then kindly spread our voice using Social Networks. Spread our word to your readers, friends, teachers, students & all those close ones who deserve to know what you know now.

Self Studies Self Studies
Weekly Quiz Competition
  • Question 1
    1 / -0
    A and B together can do a job in $$2$$ days; B and C can do it in four days; and A and C in $$2\dfrac{2}{5}$$ days. The number of days required for A to do the job alone is:
    Solution
    Let A, B, C can do a job alone in a, b, c days.
    A and B together can do in 2 days.
    $$\cfrac { 1 }{ a } +\cfrac { 1 }{ b } =\cfrac { 1 }{ 2 } $$ -------(1)
    B and C together can do in 4 days.
    $$\cfrac { 1 }{ b } +\cfrac { 1 }{ c } =\cfrac { 1 }{ 4 } $$ ------(2)
    C and A together can do in $$\cfrac{12}{5}$$ days.
    $$\cfrac { 1 }{ c } +\cfrac { 1 }{ a } =\cfrac { 5 }{ 12 } $$ -------(3)
    (1) - (2), $$\Longrightarrow \cfrac { 1 }{ a } -\cfrac { 1 }{ c } =\cfrac { 1 }{ 4 } $$ -------(4)
    (3) + (4), $$\Longrightarrow \cfrac { 2 }{ a } =\cfrac { 8 }{ 12 } $$
     $$\therefore a=3$$
    $$\therefore $$ A  can do job in 3 days.
  • Question 2
    1 / -0
    $$A$$ and $$B$$ together can finish a work in $$30$$ days. They worked on it for $$20$$ days and then $$B$$ left the work. The remaining work was done by $$A$$ alone in $$20$$ days more. In how many days can $$A$$ alone finish the work?
    Solution
    Let the total work be $$60$$ units. [LCM of $$30$$ and $$20$$]
    $$A$$ and $$B$$ do $$\dfrac {60}{30} = 2\ units/ day$$
    As they worked for $$20$$ days, they did $$20\times 2 = 40\ units$$ of work.
    Work left is $$60 - 40 = 20\ units$$
    Thus, $$20$$ units is finished by $$A$$ in $$20\ days$$.
    Hence, $$A$$ does $$\dfrac {20}{20} = 1\ unit/ day$$.
    So, $$A$$ alone can finish the work in $$\dfrac {60}{1} = 60\ days$$.
  • Question 3
    1 / -0
    $$A$$ and $$B$$ together can complete a work in $$3$$ days. They start together but, after $$2$$ days, $$B$$ left the work. If the work is completed after $$2$$ more days, $$B$$ alone could do the work in
    Solution
    Let the total unit of work be $$6$$ units (LCM of $$2$$ and $$3$$)
    $$(A + B)do = \dfrac {6}{3} = 2\ units/ day$$
    $$(A + B)'s 2\ day$$ work $$= 2\times 2 = 4\ units$$
    Work left $$= 6 - 4 = 2\ units$$
    This remaining work is done by $$A$$ in $$2$$ days.
    $$\therefore A's$$ per day work $$= \dfrac {2}{2} = 1\ unit/ day$$
    $$\therefore B's$$ per unit work $$= (A + B)'s\ work - A's\ work$$
    $$= 2 - 1 = 1\ unit/ day$$
    $$B$$ alone can complete the work in $$= \dfrac {6}{1} = 6\ days$$.
  • Question 4
    1 / -0
    $$8$$ taps of the same size fill a tank in $$27$$ minutes. If two taps go out of order, how long would the remaining taps take to fill the tank?
    Solution
    Given that,
    $$8$$ taps of the same size fill a tank in $$27$$ minutes.

    So, $$1$$ tap can fill the tank in $$8 \times 27 = 216$$ minutes

    If two taps go out of order, then the remaining taps $$= 8 - 2 = 6$$

    Therefore, Time taken  by $$6$$ taps to fill the tank $$= \dfrac{216}{6} = 36$$ minutes.
  • Question 5
    1 / -0
    $$12$$ workers can complete a piece of work in $$10$$ days. If the number of workers are reduced to $$\dfrac {1}{3}rd$$ of the original number, then how many more days would be required to complete the same work?
    Solution

    12 workers can complete a piece of work in 10 days

    I/3 rd of original No's of workers = 12*1/3 = 4 workers

    No of workers reduced then more no days are required

    12*10÷ 4 = 30

    Ans = 30 days

    hence 20 days more

  • Question 6
    1 / -0
    If $$^{n + 1}{C_3} = 4\,{\,^n}{C_2}$$ then $$n=$$
    Solution

    Given that,$$^{n+1}{{C}_{3}}={{4.}^{n}}{{C}_{2}}$$

    Then $$n=?$$


      $$ ^{n+1}{{C}_{3}}={{4.}^{n}}{{C}_{2}} $$

     $$ \Rightarrow \dfrac{\left( n+1 \right)!}{3!\left( n+1-3 \right)!}=4.\dfrac{n!}{2!\left( n-2 \right)!} $$

     $$ \Rightarrow \dfrac{\left( n+1 \right)n!}{3\times 2!\left( n-2 \right)!}=4.\dfrac{n!}{2!\left( n-2 \right)!} $$

     $$ \Rightarrow \dfrac{\left( n+1 \right)}{3}=4 $$

     $$ \Rightarrow n+1=12 $$

     $$ \Rightarrow n=12-1=11\, $$


    Hence, this is the answer.

    Option (D) is correct.
  • Question 7
    1 / -0
    A can do a piece of work in $$80 days $$.He work  at it for $$10$$ days and then $$B$$ alone finishes the work in $$42$$ day.In how much time will A and B working together,finish the work?
    Solution
    A can complete a work in $$80$$ days
    A can work in one day$$=\dfrac{1}{80}$$
    then,
    A leave the work after $$10$$ days
    $$=\dfrac{1}{80}\times 10$$
    $$=\dfrac{1}{8}$$
    Remaining work$$=1-\dfrac{1}{8}$$
    $$=\dfrac{7}{8}$$
    B complete remaining work$$=42$$ days
    $$\dfrac{7}{8}=42$$
    B can complete whole work in
    $$=\dfrac{42\times 3}{7}$$
    $$=48$$
    B can work in one day$$=\dfrac{1}{48}$$
    A and B can complete the work together$$=\dfrac{1}{80}+\dfrac{1}{48}$$
    $$=\dfrac{3+5}{240}$$
    $$=\dfrac{8}{240}$$
    $$=\dfrac{1}{30}$$
    $$30$$ days.

  • Question 8
    1 / -0
    $$3$$ letters are posted in $$5$$ letters boxes. If all the letters are not posted in the same box, then number of ways of posting is
    Solution
    According to problem,
    $$3$$ letters are posted $$5$$ boxes
    implies that,
    we have a letter and can be posted in any of the $$5$$ boxes.
    Similarly next letter can be posted in 5 ways, and the all other follow same method
    implies that
    $${\left(5\right)}^3$$
    $$ = 5 \times 5 \times 5$$
    Hence, $$ 125 $$ possible ways for posting in $$5$$ boxes.
  • Question 9
    1 / -0
    A _____ is an arrangement of all or part of set of object in a definite order.
    Solution

  • Question 10
    1 / -0
    $$8$$ men can dig a pit in $$20$$ days. If a man works one and a half as much again as a boy, then $$4$$ men and $$8$$ boys can dig it in 
    Solution
    $$\begin{array}{l} from\, the\, given\, data \\ work\, done\, by\, men=1+\frac { 1 }{ 2 }  \\ work\, done\, by\, boy=1 \\ So,\, ratio\, of\, work\, done\, by\, man\, and\, boy=3:2 \\ Now, \\ Total\, work\, =8\times 3\times 20 \\ Now, \\ 4men+9Boy=4\times 3+9\times 2 \\ =12+18 \\ =30 \\ Hence,\,  \\ No.\, of\, days=\dfrac { { 8\times 3\times 20 } }{ { 30 } }  \\ =16days \\ Hence,\, option\, \, D\, \, is\, the\, correct\, answer. \end{array}$$
Self Studies
User
Question Analysis
  • Correct -

  • Wrong -

  • Skipped -

My Perfomance
  • Score

    -

    out of -
  • Rank

    -

    out of -
Re-Attempt Weekly Quiz Competition
Self Studies Get latest Exam Updates
& Study Material Alerts!
No, Thanks
Self Studies
Click on Allow to receive notifications
Allow Notification
Self Studies
Self Studies Self Studies
To enable notifications follow this 2 steps:
  • First Click on Secure Icon Self Studies
  • Second click on the toggle icon
Allow Notification
Get latest Exam Updates & FREE Study Material Alerts!
Self Studies ×
Open Now