A boat covers 12 km upstream and 20km downstream in 4 hours while it covers 20km upstream and 12 km downstream in 4*1/2 hours. What is the velocity of current?
Let the speed of upstream be x km/hr Speed of downstream = y km/hr 12/x+20/y= 4 ………….(i) 20/x+12/y=4 1/2…………………….(ii) Adding (i) and (ii), we get 32(1/x+1/y)=17/2…………..(iii) Subtract (i) from (ii), we get 8(1/x-1/y)=1/2…………..(iv) Adding (iii) and (iv), we get 2/x=17/64+ 1/16 2/x = 21/64 x = 128/21 km/hr Now, 21/128 - 1/y = 1/16 y = 128/13 km/hr Now, rate of current = 1/2(128/13-128/21) =1.8 Km/hr
The perimeter of a square field is 10 cm more than the perimeter of a rectangle. The length of the rectangle is 60 cm which is 80% of its width. If a st...
A cylinder is inscribed in a sphere. The radius of the sphere is 4/5 times the height of the cylinder. What is the ratio of the volume of the cylinder t...
The volume of water measured on a rectangular field 400m `xx` 200m is 8000 . Find the depth (amount) of rain that has fallen.
If the area of a triangle is 864 cm2 and base: corresponding altitude is 3:4, then the altitude of the triangle is:
On a rectangular wall of length 24 metres and height 19 metres, there is a window in the shape of triangle surmounted on a square. If the base of triang...
A cuboid has dimensions 6 cm, 8 cm, and 10 cm. What is the length of the diagonal of the cuboid?
A semicircular sheet of metal of diameter 20cm is bent into an open conical cup. the capacity of the cup is. Use π = 22/7 (in cm 3 )
There's a cone of height 12cm out of which a smaller cone with the same vertex and vertical axis is cut out. What is the ratio of the volume of the larg...
The area of a square is 441 square centimeters whose side is half the radius of a circle The circumference of a circle is equal to the width of a rectan...
