14 math Unitary Method, Ratio, Percentage and Answers

1. A father can do a job as fast as two sons working together. If one son does the job alone In three hours and other does it alone in six hours, how many hours does it take the father to do job alone? (Ans : 2 hours)

2. If each of a man’s three sons works 1/8 as fast as he does and the man does a job 3 hours , how many hours does it take his sons Working together to do the job? (Ans :8 hours)

3. A man works a time as fast as any one of his helpers. If the man does a job in h hours how many hours are required for w helpers to do the job? (Ans : ah/w hours) '

4. Neetu keeps a record of time she spends practicing her music. On Monday she spend 51 hours, on Tuesday and Wednesday she spends 2 hours each day, on Thursday she spends 1 3/4 hours. How many hours will he have to spend practicing for the rest of the week in order to have an average of exactly 90 minutes each day? (Ans : 3.5 hours)

5. Mr Suman works 5 days a week and binds 35 sets of books each day . If there are7 books in a set ,how many books he binds each day? (Ans : 245)

6. If 8 men can do a job in 12days ,what is the percentage increase in the number of days required to do the job when 2 men are released? (Ans : 33 1/3%)

7. Tazrin does 1/3 of her homework and goes to dinner .After dinner she completes 3/4 of the remainder of her assignments and then decides to go a baseball game. What part of her homework will be left uncompleted if he spends no additional time on his assignments? (Ans: 1/6)

8. If 2p painter can paint 2h houses in 2w weeks ,how many painter will be needed to paint 4h houses in 4w weeks ? (Ans : 2p)

9. A man binds 112 books in one day, and his assistant works 1A as fast . How many days will it take them to bind 560 books, if each works alone on alternate days? (Ans : 24 days)

10. A regular postal clerk sorts 100 letter in c seconds, while a parttime worker requiresp seconds to sort 100 letters. How many seconds will it take them to sort 100 letters if they work together? (Ans : pc/(p+c) sec)

11.lf three boys can paint a fence in 2 days , what part of the job can be completed by two boys in 1 day? (Ans : 1/3)

12. Safwat can do a job in 45 minutes ,one of his students would require 2 hours to do the work. How long would it take to complete this task it Safwat was assisted by his student? (Ans : 6/11 hours)

13.Ethen can mow his lawn in x hrs After 2 hrs it begins to rain .What part of the lawn is left unmowed? (Ans : (x-2)/x)

14.Caesar can do a job in 10 days. After working 3 days, he hires a helper and the)’ complete the task in 5 days. How long would it take the helper to complete the task alone (Ans : 25 days)