Ques:- Thirty men take 20 days to complete a job working 9 hours a day. How many hour a day should 40 men work to complete the job?
A. 8 hrs
B. 7 1/2 hrs
C. 7 hrs
D. 9 hrs
Ques:- Gold is 19 times as heavy as water and copper is 9 times. In what ratio should these metals be mixed so that the mixture may be 15 times as heavy as water?
A. 2 : 1
B. 3 : 2
C. 4 : 3
D. 5 : 4