Question
Working alone, B can complete the work in 20 days. C is
twice as efficient as B and A takes 2 days more than it takes C to complete the work. Working together, in how much time would they be able to complete 7 such works?Solution
Time taken by B to complete the work = 20 days Time taken by C to complete the work =20/2 = 10 days Time taken by A to complete the work alone = 10 + 2 = 12 days Work done by A, B and C together in 1 day. ⇒ (1/20+ 1/10 + 1/12) = (3 + 6 + 5)/60 = 14/60 this means if would take 30/7 days for A, B and C to complete the work together ∴ Time taken A, B and C to complete 7 works = 7 × 30/7 days = 30 days
41.66% of 888 + 66.66% of 1176 = ?2 - 4√ 16 Â
Evaluate: 320 − {18 + 4 × (21 − 9)}
Simplify: 72 ÷ 6 × 3 − 8 + 4
118 × 6 + 13 + 83 = ?
Simplify the following expression:
  (400 +175) ² - (400 – 175) ² / (400 × 175)
150% of 850 ÷ 25 – 25 = ?% of (39312 ÷ 1512)
(75 + 0.25 × 10) × 4 = ?2 - 14
26% of 650 + 15% of 660 – 26% of 450 = ?
115% of 40 + 3 × 4 = ? × 11 – 8