1. It was calculated
that 75 men could complete a piece of work in 20 days. When work was scheduled to commence, it was found necessary to send 25 men to another project. How much
longer will it take to complete the work?
Answer:
30
days.
Explanation:
Before:
One day work = 1 / 20
One man’s one day work = 1
/ ( 20 * 75)
Now:
No.
Of workers = 50
One
day work =
50 * 1 / ( 20 * 75)
The total no. of days
required to complete the work = (75 * 20) / 50
= 30
2. A student divided a number by 2/3
when he required to multiply by 3/2. Calculate the percentage of error in his
result.
Answer:
0
%
Explanation:
Since 3x / 2 = x / (2 / 3)
3. A dishonest shopkeeper professes to
sell pulses at the cost price, but he uses a false weight of 950gm. for a kg.
His gain is …%. nought
Answer:
5.3 %
Explanation:
He
sells 950 grams of pulses and gains 50 grams.
If he sells 100 grams of pulses
then he will gain (50 / 950) *100 = 5.26
4. A software engineer has the capability
of thinking 100 lines of code in five minutes and can type 100 lines of code in
10 minutes. He takes a break for five minutes after every ten minutes. How many
lines of codes will he complete typing after an hour?
Answer:
250
lines of codes
5. A man was engaged on a job for 30
days on the condition that he would get a wage of Rs. 10 for the day he works,
but he have to pay a fine of Rs. 2 for each day of his absence. If he gets Rs.
216 at the end, he was absent for work for ... days.
Answer:
7
days
Explanation:
The
equation portraying the given problem is:
10 * x
– 2 * (30 – x) = 216 where x is the number of working
days.
Solving
this we get x = 23
Number
of days he was absent was 7 (30-23) days.
6. A contractor agreeing to finish a
work in 150 days, employed 75 men each working 8 hours daily. After 90 days,
only 2/7 of the work was completed. Increasing the number of men by ________
each working now for 10 hours daily, the work can be completed in time.
Answer:
150
men.
Explanation:
One
day’s work = 2 / (7 * 90)
One
hour’s work = 2 / (7 * 90 * 8)
One
man’s work = 2 / (7 * 90 * 8 * 75)
The
remaining work (5/7) has to be completed within 60 days, because the total
number of days allotted for the project is 150 days.
So
we get the equation
(2 * 10 * x *
60) / (7 * 90 * 8 * 75) =
5/7 where x is the number of men
working after the 90th day.
We get x = 225
Since we have 75 men already, it
is enough to add only 150 men.
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