Quantitative Aptitude - Arithmetic Ability Questions

Select the odd word/letters/number/number pair from the given alternatives.

If 7 times the seventh term of an Arithmetic Progression (AP) is equal to 11 times its eleventh term, then the 18th term of the AP will be

50 litre mixture of water and alcohol contains 10% alcohol. How much more alcohol must be added to make the strength of alcohol 40% in the new mixture?

X does 25% of a work in 20 days. Y joins X and they together finish the remaining work in 15 days. Y alone can do the whole work in ___ days.

The percentage change of a number when it is first decreased by 10% and then increased by 10% is

Both A and B together can complete a work in 20 days and B alone can complete the same work in 36 days. In how many days will A alone complete the work?

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 alternatives.

When [x + (1/x)] = 5, then what is the value of [x – (1/x)]?