Question
25 men can complete a piece of work in 13 days. One man
starts the work and after every day one more man joins the work and this continues till the work is completed. Then, in how many days will the work be completed?Solution
Let 1 day work of 1 man = 1 units So total work = 25 ×13 = 325 units Suppose after n days work is finished. So, 1 + 2 + ………… +n = 325 ⇒ (n(n+1))/2 = 325 n² + n – 650 = 0 n² + 26n – 25n – 650 = 0 n(n + 26 ) – 25(n + 26) = 0 (n - 25) (n + 26) ∴ n = 25 Hence, the work will be finished in 25 days.
It is invariably life in the fast pane for aircraft fitted with this engine, often used for troop transport or medevacking operations.
Steal someone’s _______________
An idiom/phrase is given in bold. Following this idiom/phrase are given three sentences, which use the given idiom/phrase. The idiom/phrase may or may ...
An idiom/phrase is given in bold. Following this idiom/phrase are given three sentences, which use the given idiom/phrase. The idiom/phrase may or may ...
Which of the Phrases (a), (b), (c) and (d) should replace the highlighted phrase in the sentence to make it grammatically correct? If the sentence i...
Interns are neither fish nor fowl .
To move heaven and earth Â
Select the most appropriate meaning of the given idiom.
 Raise the bar
An idiom/phrase is given in bold. Following this idiom/phrase are given three sentences, which use the given idiom/phrase. The idiom/phrase may or may ...
They doubt the maid has got _____________ so they do not keep much money at home.