Question
If the speed of stream is 3 km/h, a boat takes 9 hours
to travel 112 km downstream and 110 km upstream. What is the speed (in km/h) of the boat in still water?Solution
Given: Stream speed = 3 km/h Downstream: 112 km Upstream: 110 km Total time = 9 hours Let boat speed in still water = x km/h Downstream speed = x + 3 Upstream speed = x − 3 Time = Distance / Speed 
Multiply both sides by (x + 3)(x − 3): 
Solve using quadratic formula: 
If p = 24 - q - r and pq + r(q + p) = 132, then find the value of (p² + q² + r²).
((99.9 - 20.9)² + (99.9 + 20.9)² )/(99.9 x 99.9 + 20.9 x 20.9) = ?
...
Find the value of the given expression-
(4x+4 -5× 4x+2) / 15×4x – 22×4x
If 4x² + y² = 40 and x y = 6, then find the value
of 2x + y?
If p = 40 - q - r and pq + r(q + p) = 432, then find the value of (p² + q² + r²).
47.98 × 4.16 + √325 × 12.91 + ? = 79.93 × 5.91
If x + y = 4 and (1/x) + (1/y) = 24/7, then the value of (x3 + y3).
- If p = 20 - q - r and pq + r(p + q) = 154, then find the value of (p² + q² + r²).
If a = (√2 - 1)1/3, then the value of (a-1/a)3 +3(a-1/a) is:
