Let the speed of boat in still water be 'v' km/h. ATQ, 48/(v + 4) + 48/(v - 4) = 5 Or, 48 X (v - 4 + v + 4) = 5 X (v2 - 16) Or, 48 X 2v = 5v2 - 80 Or, 5v2 - 96v - 80 = 0 Or, 5v2 - 100v + 4v - 80 = 0 Or, 5v(v - 20) + 4(v - 20) = 0 Or, (5v + 4) (v - 20) = 0 So, 'v' = 20 or 'v' = - (4/5) But speed cannot be negative. So, 'v' = 20 Upstream speed of boat = 20 - 4 = 16 km/h Therefore, upstream distance cover by boat in 150 minutes = 16 X (150/60) = 40 km
If the radius of a circle is 15 cm, then which of the following is true regarding the length of the chord (L)?
A sector of a circle has a central angle of 120° and a radius of 10 cm. Find the area of the sector.
Find the area of the sector of a circle with radius 14 cm and central angle 90°.
"In the given figure, 'O' is the center of the circle. If XR = 24 cm and RS = 18 cm, find the length of XO."
A semicircle has a radius of 7 cm. What is the perimeter of the semicircle?
In a circle AB is diameter & C is a point on circumference such that AC = 8 cm & BC = 15 cm then find the area of circle ?
A metal wire when bent in the form of a square encloses an area 1089 cm 2 , if the same wire is bent in the form of a circle, then its area is?
In a circle, the length of a chord AB is 48 cm & radius is 25 cm. Find the distance between centre and chord.
Find out the circumference of a sector whose radius is 7 cm and it makes the angle of 45° at the centre.
In the given figure, AB is diameter and CD ∥ AB. If the value of ∠BPC is 55°, then find the value of ∠BCD.
