SBI PO Time and Work Quiz practice set 1

1 . Amit and Sujit together can complete an assignment of data entry in 5 days. Sujit’s speed is 80 % of Amit’s speed and the total key depressions in the assignment are 5,76,000. What is Amit’s speed in key depressions per hour If they work for 8 hours a day ? A.   4800 B.   6400 C.   8000 D.   7200 2 . 4 men can complete a piece of work in 2 days. 4 women can complete the same piece of work in 4 days whereas 5 children can complete the same piece of work in 4 days. If , 2 men, 4 women and 10 children work together, in how many days can the work be completed? A.   1 day B.   3 days C.   2 days D.   4 days 3 . 12 men can do a piece of work in 10 days. How many men would be required to do the same work in 8 days ? A.   14 B.   18 C.   16 D.   None of these 4 . ‘A’ can complete a piece of work in 12 days. ‘A’ and ‘B’ together can complete the same piece of work in 8 days. In how many days can ‘B’ alone complete the same piece of work? A.   15 days B.   18 days C.   24 days D.   28 days 5 . 12 men take 36 days to do a work while 12 women complete $3\over 4$ th of the same work in 36 days. In how many days 10 men and 8 women together will compelete the same work? A.   6 B.   27 C.   12 D.   None of these 6 . Three men, four women and six children can complete a work in 7 days. A woman does double the work a man does and a child does half the work a man does. How many women Alone can complete this work in 7 days ? A.   8 B.   7 C.   12 D.   None of these 7 . M and N can do a work in 10 days and 15 days respectively. If M starts on the work and both work alternately day after day. in how many days will the work be completed ? A.   10 B.   12 C.   8 D.   9 8 . 6 women and 6 men together can complete a piece of work in 6 days. In how many days can 15 men alone complete the piece of work if 9 women alone can complete the work in 10 days? A.   6 B.   5 C.   7.2 D.   None of these 9 . Four examiners can examine a certain number of answer papers in 10 days by working for 5 hours a day. For how many hours in a day would 2 examiners have to work in order to examine twice the number of answer papers in 20 days ? A.   8 hours B.   7$1\over 2$ hours C.   10 hours D.   8$1\over 2$ hours

Answers & Solutions   1 .     Answer : Option C Explanation : Let Amit's spped be x key depressions per day. Sujit's speed $4x\over 5$ key depressions per day 5$\times$ + 5 $\times$ $4x\over 5$ = 576000 $\Rightarrow$ 9 $x$ = 576000 $\Rightarrow$ $x$ = $576000\over 9$ = 64000 Amit's speed per hour = $64000\over 8$= 8000 2 .     Answer : Option A Explanation : 4 × 2 men $\cong $4 × 4 women = 20 children 2 men $\cong $ 4 women $\cong $ 5 children 2 men + 4 women + 10 children = 20 children $M_1 D_1 = M_2 D_2$ 5 x 4 = 20 x D$_2$ $\Rightarrow$ D$_2$ = 1 day 3 .     Answer : Option D Explanation : Days $\,\,\,\,\,\,\,\,\,$ Men 10$\uparrow$$\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,$12$\downarrow$ $\,$ 8$\uparrow$$\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,$ $x$$\downarrow$ Where $x$= No. of Men 8 : 10 :: 12 : $x$ $\Rightarrow$ $8 \times x = 10 \times 12 $ $\Rightarrow$ x = $10 + 12\over 8$ = 15 4 .     Answer : Option C Explanation : A’s 1 day’s work = $1\over 12$ (A + B)’s 1 day’s work = $1\over 8$ B’s 1 day’s work = $1 \over 8$ - $1\over 12$ = $3 - 2 \over 24$ = $1\over 24$ B alone can do the work in 24 days. 5 .     Answer : Option B Explanation : In 36 days 12 men can do 1 complete work. In 36 days 12 women can do $3\over 4$ th of the work Since time and the no, of persons in the same is both casses, 1 woman’s daily work $3\over 4$ th of 1 man’s daily work 8 woman’s daily work = $3\over 4$ × 8 = 6 meri’s daily work (10 men + 8 womens daily work) = (10 men + 6 men) = 16 men’s daily work. 12 men can do the work is 36 days 16 men can do the work is 36 × $12\over 16$ = 27 days. 6 .     Answer : Option B Explanation : 2 men = 1 woman 1 man = $1\over 2$ women 3 men = $3\over 2$ women Again, 2 children = 1 man = $1\over 2$ women 1 child = $1\over 4$ women 6 children = $6\over 4$ = $3\over 2$ women Now, three men, four women and six children = $3\over 2$ + 4 + $3\over 2$ = 7 women Hence, 7 women complete the work in 7 days 7 .     Answer : Option B Explanation : Work done in 1st two days = $1 \over 10$ + $1\over 15$ = $ 3 + 2 \over 30$ = $1 \over 6$ Number of days = 12 8 .     Answer : Option D Explanation : $M_1D_1\over W_1$ = $M_2D_2\over W_2$ $\Rightarrow$ $ 6\times 6\over W_1 $ = $9 \times 10 \over 1$ $\Rightarrow$ $W_1$ = $6 \times 6\over 9 \times 10$ = $2\over 5$ Part of work done by 6 women in 6 days = $2 \over 5$ Part of work done by 6 men in 6 days = 1 – $2 \over 5$ = $3 \over 5$ $M_1D_1\over W_1$ = $M_2D_2\over W_2$ $\Rightarrow$ $ 6\times 6\over W_1 $ $\Rightarrow$ $6 \times 6 \over {3\over 5}$ = $ 15 \times D_2 \over 1$ $\Rightarrow$ $15 \times D_2$ = $ 6 \times 6 \times 5\over 3$ = 60 $\Rightarrow$ $D_2$ = $60\over 15$ = 4 day 9 .     Answer : Option C Explanation : Examiners$\,\,\,\,\,\,\,\,\,\,$ Work$\,\,\,\,\,\,\,\,\,\,$ Days$\,\,\,\,\,\,\,\,\,\,$ Hours / day $\,\,\,\,\,\,\,\,\,\,$4$\uparrow$$\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,$1$\downarrow$$\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,$10$\uparrow$$\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,$5$\downarrow$ $\,\,\,\,\,\,\,\,\,\,$2$\uparrow$$\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,$2$\downarrow$$\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,$20$\uparrow$$\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,$$x$$\downarrow$ (2 : 4), (1 : 2) & (20 : 10) :: (5 : $x$) $\Rightarrow$$2 \times 20 \times x= 4 × 10 × 5 × 2$ $\Rightarrow$ $x$ = $4 \times 10 \times 5 \times 2 \over 2\times 20$ = 10 hours