Question
An alloy of copper and tin contains 85% of copper. If 28
kg of more tin is added to the alloy, the copper content gets reduced to 50%. Find the quantity of the new alloy.Solution
Ratio of copper to tin in the alloy = 17:3 Let the quantity of copper and tin in the alloy be 17x kg and 3x kg, respectively. According to question, 17x = 3x + 28 x = 2 kg So, the quantity of new alloy = 17x + 3x + 28 = 20x + 28 ⇒ 40 + 28 = 68 kg
900 Â Â Â 90Â Â Â 18Â Â Â ? Â Â Â Â 2.16Â Â Â Â 1.08
78, 80, 84, ?, 108, 140
5 6 14 45 ? 925
...1, 26, 75, 156, 277, ?
138, 140, 152, 174, ?, 248
11, ? 220,  660, 1320,  1320Â
114, 134, 174, 254, 414, ?Â
14 6 4 4 ? 48
...What should come in place of (?) question mark in the following number series.
5, 11, 23, 47, 95, ?
7, 8, 18, 57, 232, ?