The radius of a circular wheel is 1 m. How many revolutions will it make in traveling 11 km ?
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Solution
Number of revolutions =
A group of men decided to do a work in 10 days, but five of then became absent. If the rest of the group did the work in 12 days. Find the original number of men ?
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Solution
Let there were x men originally
∴ x × 10 = (x – 5) × 12
x = 30 men
A shopkeeper marks the prices of his goods at 20% higher than the original price. After that he allows a discount of 10%. What profit or loss did he get ?
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Solution
20 – 10 –
∴ % Profit = 8%
In what time will Rs 8500 amount to Rs 15767.50 at 4½ percent per annum ?
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Solution
Simple interest = 15767.50 – 8500 = 7267.5
∴ 7267.5 = × T
T = 19 years
A can do a work in 6 days. B takes 12 days. C takes as long as A and B would take working together. How long will it take B and C to complete the work together ?
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Solution
12 (LCM)
∴ Required time to A & B working together = = 4 days
∴
12 (LCM)
∴ Required time to B & C working together = days
A man can row upstream at 10 km/hr and downstream at 18 km/hr. Find the rate of the current :
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Solution
Speed of current = = 4 km/hr
A train traveling at 30 km an hour took 13½ sec in passing a certain point. Find the length of the train :
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Solution
Length of train = m
A constable is 117 m behind a thief. The constable runs 37 m and the thief 24 m in a minute. In what time the constable will catch the thief ?
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Solution
Relative speed of constable = 37 – 24 = 13 m/m
∴ Required time = min.
If 3x – = 12 then what is the value of ?
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Solution
⇒
∴
The marked price of an article is 16% higher than cost price. A discount of 15% is given on marked price. Find the percent profit/loss :
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Solution
Let cost price is Rs 100
∴ Marked price = Rs 116
Selling price = = Rs 98.60
∴ % Loss = 100 – 98.6 = 1.4