**811. P and Q can complete a work in 15 days and 10 days respectively. They started the work together and then Q left after 2 days. P alone completed the remaining work. The work was finished in__________days.****A. 12**

B. 15

C. 22

D. 20

**Explanation:****Work done by P in 1 day = 1/15****Work done by Q in 1 day = 1/10****Work done by P and Q in 1 day = 1/15 + 1/10 = 1/6****Work done by P and Q in 2 days = 2 × (1/6) = 1/3****Remaining work = 1 – 1/3 = 2/3****Time taken by P to complete the remaining work 2/3 = (2/3) / (1/15) = 10 days****Total time taken = 2 + 10 = 12 days**

**812. A and B can finish a work 30 days if they work together. They worked together for 20 days and then B left. A finished the remaining work in another 20 days. In how many days A alone can finish the work?**

A. 70

B. 50

C. 40**D. 60**

**Explanation:****Amount of work done by A and B in 1 day = 1/30****Amount of work done by A and B in 20 days = 20 × (1/30) = 20/30 = 2/3****Remaining work – 1 – 2/3 = 1/3****A completes 1/3 work in 20 days****Amount of work A can do in 1 day = (1/3)/20 = 1/60****=> A can complete the work in 60 days**

**813. A is thrice as good as B in work. A is able to finish a job in 60 days less than B. They can finish the work in___________days if they work together.**

A. 18 days**B. 22 ½ days**

C. 24 days

D. 26 days

**Explanation:****If A completes a work in 1 day, B completes the same work in 3 days****Hence, if the difference is 2 days, B can complete the work in 3 days****=> if the difference is 60 days, B can complete the work in 90 days****=> Amount of work B can do in 1 day= 1/90****Amount of work A can do in 1 day = 3 × (1/90) = 1/30****Amount of work A and B can together do in 1 day = 1/90 + 1/30 = 4/90 = 2/45****=> A and B together can do the work in 45/2 days = 22 ½ days**

**814. Two taps X and Y can fill a tank in 10 hrs. and 15 hrs.respectively. If the both taps are opened together, the tank will be full in_________?**

A. 3 hrs.

B. 4 hrs,

C. 5 hrs.**D. 6 hrs.**

**Explanation:****X’s 1 hour work = 1/10****Y’s 1 hour work = 1/15****(x+y)’s 1 hour work = 1/10+1/15=5/30=1/6****Both the taps can fill the tank in 6 hrs.**

**815. A, B and C together earn Rs.150 per day while A and C together earn Rs.94 and B and C together earn Rs.76. The daily earning of C is:__________?**

A. 10 Rs,

B. 15 Rs,**C. 20 Rs.**

D. 25 Rs.

**Explanation:****B’s daily earning = Rs.(150-94)= Rs.56****A’s daily earning = Rs.(150-76)= Rs.74****C’s daily earning = Rs.[(150-(56+74)]=Rs.20**

**816. If 3 men or 4 women can construct a wall in 43 days, then the number of days that 7 men and 5 women take to construct it is :**

A. 12 days

B. 14 days**C. 16 days**

D. 18 days

**817. If 6 men can make 10 sofas in 2 days, then 8 men can make 8 sofas in__________?**

A. 1.8 days

B. 1.5 days**C. 1.2 days**

D. 1 day

**Explanation:****Time is****directly proportional to number of sofas****inversely proportional to number of people No. of days****= (6/8)*(8/10)*2****= 1.2 days**

**818. If 10 workers can make 10 tables in 10 days, then how many days would it take for 5 workers to make 5 tables?**

A. 1

B. 5**C. 10**

D. 25

**Explanation:****10 workers make 10 tables in 10 days. 1 worker makes 1 table in 10 days. Similarly, 5 workers can make 5 tables in 10 days.**

**819. If 6 men take 9 days to complete a work, how many men can complete the work in 3 days?**

A. 2 men

B. 12 men

C. 9 men**D. 18 men**

**Explanation:****For the work to be completed in 9 days,****6 men are required. Time and men are inversely proportional. For the work to be completed in 3 days,****6*9/3 = 18 men are required**

**820. Assume that 20 cows and 40 goats can be kept for 10 days for Rs.460. If the cost of keeping 5 goats is the same as the cost of keeping 1 cow, what will be the cost for keeping 50 cows and 30 goats for 12 days?****A. Rs.1104**

B. Rs.1000

C. Rs.934

D. Rs.1210

**Explanation:****Assume that cost of keeping a cow for 1 day = c ,****cost of keeping a goat for 1 day = g****Cost of keeping 20 cows and 40 goats for 10 days = 460****Cost of keeping 20 cows and 40 goats for 1 day = 460/10 = 46****=> 20c + 40g = 46****=> 10c + 20g = 23 —(1)****Given that 5g = c****Hence equation (1) can be written as 10c + 4c = 23 => 14c =23****=> c=23/14****cost of keeping 50 cows and 30 goats for 1 day****= 50c + 30g****= 50c + 6c (substituted 5g = c)****= 56 c = 56×23/14****= 92****Cost of keeping 50 cows and 30 goats for 12 days = 12×92 = 1104**