Question
Durgesh can complete a task alone in 21 days. If Vikash
works alone for 8 days and then leaves, Durgesh can finish the remaining work in 7 days. Satish is 25% less efficient than Durgesh. If Vikash and Satish work together for ‘x’ days and then leave, Durgesh can complete the remaining work alone in 6 days. Determine the value of ‘x’.Solution
Answer: A Let the efficiency of Durgesh alone = ‘y’ units/day Then, total work = 21 × y = ‘21y’ units Let the efficiency of Vikash = ‘z’ units/day We have, 8 × z + 7 × y = 21y Or, 8z = 14y So, z:y = 14:8 = 7:4 So, ratio of efficiencies of Vikash and Durgesh is 7:4, respectively So, efficiency of Vikash = (7y/4) = ‘1.75y’ units/day Efficiency of Satish = y × 0.75 = ‘0.75y’ units/day Combined efficiency of Vikash and Satish = 1.75y + 0.75y = ‘2.5y’ units/day According to the question, 2.5y × x + y × 6 = 21y Or, 6y + 2.5xy = 21y Or, 2.5xy = 15y So, x = 15 ÷ 2.5 = 6
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) = ?
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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:
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