Quantitative Aptitude - Arithmetic Ability Questions

7C2- 7 = 14

Cost price of the article is given by

= 400x100/(20+20)

= Rs.1000

P.W=Rs.100×2310100+15×52 = Rs.1680

Let C's age be x years.
Then, B's age = 2x years.
A's age = (2x + 2) years.
(2x + 2) + 2x + x = 27
5x = 25 => x = 5
Hence, B's age = 2x = 10 years.

Substitute sensible numbers and work out the problem. Then change the numbers back to letters. For example if the machine puts 6 caps on bottles in 2 minutes, it will put 6 /2 caps on per minute, or (6 /2) x 60 caps per hour. Putting letters back this is 60c/m.If you divide the required number of caps (b) by the caps per hour you will get time taken in hours. This gives bm/60c

More Men, Less Hours {Indirect Proportion}

Less Days, More Hours {Indirect Proportion}

 men15 : 10days12 : 18 ⋮⋮ 6:x

=> 15 * 12 * x = 10 * 18 * 6

=>x = 6

work done=total number of person x number of days;
half of work done = 140 x 66;
For half of remaining work 25 extra men are added.
Therefore, total men for half work remaining = 140 + 25 = 165;
Let 2nd half work will be completed in K days;
140 x 66 = 165 x K
K = 122;
Hence, extra days => 122-120 = 2days.