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.
- What approximate value will come in place of the question mark (?) in the following question? (Note: You are not expected to calculate the exact value.)
12.5% of 6400 + (17 × 25) = ?% of 2200+ 125
What approximate value will replace the question mark (?) in the following?
? –...
? * 7.05 = (360.06 ÷ 11.02) % of 4290 - 759.91
Solve the following expression and calculate the approximate value.
1727.8 + 2196.75 + 3 × 11.8 × 12.9 × 24.75
49.99% of 639.99 + 159.98% of 49.99 = ?2
19.99% of 79.98 = ?2– 159.99% of 12.5
What approximate value will come in place of the question mark (?) in the following question? (Note: You are not expected to calculate the exact value.)...
570.11 ÷ 18.98 × 5.14 – 123.9 = √?
What approximate value should replace the question mark?
9.96% of 1200.10 − 25% of 4800 = ? − 7000.20
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