Quantitative Aptitude - Arithmetic Ability Questions

In the following question, four number pairs are given. The number on left side of (–) is related to the number on the right side of (–) with some Logic/Rule/Relation. Three are similar on basis of same Logic/Rule/Relation. Select the odd one out from the given options.

A boat covers a distance of 14 km upstream and 16 km downstream in 9 hours. It covers a distance of 12 km upstream and 40 km downstream in 11hours. What is the speed (in km/hr) of the boat in still water?

Of the 3 numbers whose average is 40, the first is 1/3 rd the sum of other 2. What is the first number?

A, B and C can complete a work in 20, 24 and 30 days respectively. All three of them starts together but after 4 days A leaves the job and B left the job 6days before the work was completed. C completed the remaining work alone. In how many days was the total work completed?

The simple and compound interest that can be earned in two years at the same rate is Rs 1,000 and Rs 1,040 respectively. What is the rate (percent per annum) of interest?

A student, by mistake, wrote 64 in place of 46 as a number at the time of finding the average of 10 given numbers & got the average as 50. The correct average of the numbers is

The average weight of 3 men A, B and C is 84 Kg. Another man D joins the group and the average now becomes 80 Kg. If another man E whose weight is 3 Kg more than that of D, replaces A then the average weight of B, C, D and E becomes 79 Kg. What is the weight of A?

For what value of 'y', x2 + 112x + y2 is a perfect square?