If 5 men working for 6 hours a day can reap a field in 20 days, in how many days will 15 men reap the field, working 8 hours a day ?
(a) 5 days
(b) 6 days
(c) 7 & 1/2 days
(d) 9 days
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Unitary Method Problem
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Let the rate per worker = 1 unit per hour.[email protected] wrote:If 5 men working for 6 hours a day can reap a field in 20 days, in how many days will 15 men reap the field, working 8 hours a day ?
(a) 5 days
(b) 6 days
(c) 7 & 1/2 days
(d) 9 days
Rate for 5 men = 5 units per hour.
Work produced by 5 men working 6 hours per day = 5*6 = 30 units per day.
Work produced in 20 days = 20*30 = 600 units.
Thus, one field = 600 units.
Rate for 15 men = 15 units per hour.
Work produced by 15 men working 8 hours per day = 15*8 = 120 units per day.
At a rate of 120 units per day, the time required by 15 men to produce 600 units = 600/120 = 5 days.
The correct answer is A.
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theCEO
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only change 2 of the 3 items at once, keep the other variable constant.[email protected] wrote:If 5 men working for 6 hours a day can reap a field in 20 days, in how many days will 15 men reap the field, working 8 hours a day ?
(a) 5 days
(b) 6 days
(c) 7 & 1/2 days
(d) 9 days
05men ..... 6hr ..... 020days
05men ..... 1hr ..... 120days
05men ..... 8hr ..... 015days
15men ..... 8hr ..... 005days
ans= a
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Is there any other shortcut method for solving this problem ? This solution no doubt helped me but also confused me and can confuse in future which could hurt my score ?? So if any other simpler method ??
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Use the following formula:[email protected] wrote:Is there any other shortcut method for solving this problem ? This solution no doubt helped me but also confused me and can confuse in future which could hurt my score ?? So if any other simpler method ??
(workers)(hours)(days) = (workers)(hours)(days)
Since 5 men working 6 hours per day require 20 days, and we must determine how days are required by 15 men working 8 hours per day, we get:
5*6*20 = 15*8*x
2*20 = 8x
40 = 8x
x = 5.
The correct answer is A.
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Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.
As a tutor, I don't simply teach you how I would approach problems.
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