Question
When travelling downstream, a boat takes 4.25 hours to
travel 187 km. If the speed of the stream is (5/11)th of downstream speed of the boat, then find the time taken by the boat to cover 240 km in still water.Solution
Downstream speed of the boat = 187/4.25 = 44 km/hr Speed of the stream = 44 x (5/11) = 20 km/hr So, speed of the boat in still water = 44 – 20 = 24 km/hr Required time taken = 240/24 = 10 hours
If x −y =4and xy =45,thenthevalueof x 3 −y3is:
Find the values of 'a' and 'b', so that the polynomial x3 − ax2 − 13x + b has (x−1) and (x+3) as factors:
- If (x + y + z) = 10 and (x 2 Â + y 2 Â + z 2 ) = 52, then find {z(x + y) + xy}.
if x2 – 2x + 1 = 0, then find the value of (x7 + x5 + x4 + x2)/x ?
A dishonest dealer claims to sell goods at cost price but uses a false weight of 900g instead of 1kg. What is his profit percentage?
Evaluate (998)3 without multiplying directly.
If 8x3Â - 125y3Â = (2x - Ay) X (Bx2Â + 25y2Â + Cxy), then find the value of 3 X (2A + 6B) - 2C.
If (x2Â + y2Â + z2Â - 4x + 6y + 13) = 0, then find the value of (x + y + z).
Find the value of ‘x’ in the given expression:
(49/16)x × (64/343)x-1 = 4/7
