A woman who goes to work long before sunrise every morning gets dressed in the dark. In her socks drawer she has 9 black and 12 blue socks. What is the probability that her first pick was a black sock, but her second pick was a blue socks?
In a business Nirav invests Rs.72000. After 6 months his uncle invests Rs.54,000. After one year they got a profit of Rs.22,000. Then uncle gets his share as
From a point on a bridge across a river, the angles of depression of the banks on opposite sides of the river are 60Â° and 45Â° respectively. If the bridge is at a height of 9 meter from the banks then find the width of the river? Assume both the banks are at same ground level.
OPtion
1) 14.02 m
2) 14.11 m
3) 14.20 m
4) 14.40 m
5) 14.73 m
6) 14.35 m
7) 14.05 m
8) 14.53 m
9) 14.63 m
10) None of these
Solution
Let A and B be the two sides of the river and C be the point on the bridge. D is a point on straight line between A and B such that CD = 9 meters
Width of the river would = AD+BD
In right angled triangle ACD,
tan 60Â° = CD/AD
=> âˆš3 = 9/AD
=> AD = 9/âˆš3 = 3âˆš3
In right angled triangle BCD,
tan 45Â° = CD/BD
=> 1 = CD/BD
=> CD = BD = 9 meters
So the width of the river is AD+BD = 9+3âˆš3 = ~14.20 meters
A certain number of men can finish a piece of work in 30 days. If however there were 15 men less it will take 30 days more for the work to be finished. How many men were there originally?
A certain number of men can finish a piece of work in 30 days. If however there were 15 men less it will take 30 days more for the work to be finished.
So the no. of days are doubled (from 30 to 60) , it means no. is men is reduced to half.
so earlier, there were 15*2= 30 men.
Initially two cups of same volume are present with milk filled upto 2/7th and 3/7th of their volumes. Water is then filled in both the cups (completely). Then two mixtures are mixed. Find the ratio of water to milk in the mixture?
Let the cups volume be x.
here we assume that water fills both volumes completely
after mixing , total milk is -> 2/7x + 3/7x = 5/7x
after mixing , total water is -> 5/7x + 4/7x = 9/7x
therefore water to milk ratio is (9/7)/(5/7) = 9:5