Question
A boat can cover 80 km upstream and 200 km downstream in
14 hours. Speed of the stream is how much less than the speed of the boat in still water if the boat can cover 64 km upstream and 160 km downstream in 10 hours?Solution
ATQ, Let the upstream speed and downstream speed of the boat be x km/h and y km/h, respectively. So according to question: 80/x + 200/y = 14 ………………. (i) Also, 64/x + 160/y = 10 ……….. (ii) Solving (i) and (ii), we get x = 16 and y = 32 So, the upstream speed and downstream speed of the boat are 16 km/h and 32 km/h, respectively. Speed of the boat in still water = (16 + 32)/2 = 24 km/h Speed of the stream = (32 – 16)/2 = 8 km/h So, the desired difference = 24 – 8 = 16 km/h
The length of the rectangle is triple its breadth. If the perimeter of the rectangle is 40 m, then find the area (in m2) of the rectangle.
If the curved surface area and the radius of a cylinder are 550 cm2 and 7 cm, respectively, then find the volume (in cm3) of the c...
The cost of fencing a rectangular garden at Rs. 10/metre is Rs. 1000. If the ratio of the length to breadth is 3:2, find the area of the garden.
The height of a right circular cone is 18 cm. If the volume of the cone is 4158 cm³, find the ratio of the height of the cone to...
If the area of a triangle is 1350 cm2 and base: corresponding altitude is 3:4, then the altitude of the triangle is:
The breadth of a rectangle is increased by 10 cm, it will become twice the length of the rectangle. If the new perimeter is 336 cm, then find the origin...
 What will be the total surface area of a triangular pyramid whose sides are all 1 cm long?
Angle bisectors of Q and R meet at point S, inside the triangle PQR. If angle QSR = 132Ëš , then the measure of angle P is:
The volume of a solid cube is 2197 m3. If whole cube is to be painted at a rate of Rs. 3.5 per m2, then what will be the cost of p...
On a rectangular wall of length 25 metres and height 20 metres, there is a window in the shape of triangle surmounted on a square. If the base of triang...
Relevant for Exams:
