Explanation:

Of the 65 families in a locality, 45 have children and 10 have retired individuals as members. Of the families, 8 have both children and retired individuals as members. How many of the families have neither children nor retired individuals as members? Correct Answer 18 Number of families having children or retired individuals or both = 45 + 10 - 8 = 47 So, number of families having neither children nor retired individuals = 65 - 47 =  18.

Explanation:

A man can row downstream at 10 kmph and upstream at 5 kmph. The man's rowing rate in still water is ---- Correct Answer 7.5 km/hr Let the man's rowing rate and stream's flowing rate be U and V respectively. So,     U + V = 10 And,   U - V = 5 - - - - - - - - - - - - - - - - - - - - - - - U + U = 10 + 5  [By addition] or,  2U = 15 So,  U = 7.5 km/hr

Explanation:

The diameter of a wheel is 63 cm. Distance traveled by the wheel in 100 revolutions is ---- Correct Answer 198 meters Radius of the wheel, R = 63/2 cm = 31.5 cm Distance travelled in one revolution = 2 π R = 2 π x (31.5) = 63 π  cm = 0.63 π meters  So, distance travelled in 100 revolutions = 100 x 0.63 π  = 63 x 3.1416 =  198 meters

Explanation:

0.777777/0.011=? Correct Answer 70.707 0.7777770.011  = 777777×100011×1000000 = 70707×10001000000 = 707071000 = 70.707

Explanation:

The arithmetic mean of the set of observations 1, 2, 3, --------n is ----- Correct Answer n+1/2 The arithmetic mean of a set of numbers is equal to the sum of the numbers divided by the total number of numbers. In this case, we want to find the arithmetic mean of the set of observations from 1 to n.The sum of the numbers from 1 to n can be found using the formula for the sum of an arithmetic series:sum = (n/2)(first term + last term)In this case, the first term is 1, the last term is n, and the common difference is 1. Therefore, we have:sum = (n/2)(n+1)The total number of numbers in the set is n, so the arithmetic mean is:mean = sum/nSubstituting the expression for sum, we get:mean = [(n/2)(n+1)]/nSimplifying, we get:mean = (n+1)/2Therefore, the arithmetic mean of the set of observations 1, 2, 3, ..., n is (n+1)/2

Explanation:

If 15 men can reap a field in 35 days, in how many days will 21 men reap the field? Correct Answer 25 days 15 men can reap the field in 35 days 1 man can reap the field in 35 x 15 days So, 21 men can reap the field in 35 x 15 / 21 =  25 days

Explanation:

If the circumference of a circle is increased by 50%, its area will be increased by : Correct Answer 125% Circumference of a circle increases only with radius. Therefore, radius of the circle gets increased by 50%. Now, new radius = R + 50% of R = 1.5R Initial area =  π R2 New area =  π (1.5R)2 = 2.25 π R2 Percent increase = ((2.25 π R2) - (π R2)} / (π R2)  x 100% = 125%

Explanation:

The average of 7 numbers of 40. If 3 more numbers, with an average of 21, are added to these numbers, what will be the average of the combined 10 number? Correct Answer 34.3 The average of 7 numbers of 40. If 3 more numbers, with an average of 21, are added to these numbers, what will be the average of the combined 10 number? Total of 7 numbers = 7 x 40 = 280 Total of 3 numbers = 3 x 21 = 63 Total of (7 + 3 = 10) numbers  = 280 + 63 = 343 So, average = 343 / 10 = 34.3

Explanation:

A number consists of two digits, whose sum is 10. If 18 is subtracted from the number, digits are reversed. The number is ---- Correct Answer 64 [***This question is erroneous. Correction: If '14' is subtracted.....] Let,  X and Y be the decimal and unit place digits respectively. So, the number is (10X + Y). If the digits gets reversed, the number becomes (10Y + X). Now,  X + Y = 10 or, X = 10 - Y Again,  10X + Y - 14 = 10Y + X or,  10(10 - Y) - 14 = 10Y + (10 - Y) or,  100 - 10Y - 14 = 10Y + 10 - Y or,  10Y + 10Y - Y = 100 - 14 - 10 or,  19Y = 76 or,  Y = 4 So,  X = 10 - Y = 10 - 4 = 6 Therefore the number is 64.

Explanation:

A cooperative collected Tk. 5,000 from its members. if each member contributed at least Tk. 240. What is the greatest number of members that the cooperative could have? Correct Answer 20 If each member contributed the minimum 240 TK, the number of members will be the greatest. So, the greatest number of members possible = 5000/240 ≈ 20

Explanation:

A rectangular carpet, that is 9 feet by 12 feet, covers 60% of a rectangular floor. What is the area of the floor? Correct Answer 180 square feet Area of the carpet = 9 x 12 = 108 sq ft 60% of the floor = 108 sq ft So, total or 100% floor area = 108 x 100 / 60 = 180 sq ft

Explanation:

If the cooperative (from the previous question) has the greatest number of members possible (with a minimum of Tk. 240 contribution) and all members except one paid exactly Tk. 240, then how much did the member who paid higher than the rest, pay? Correct Answer Tk. 440 Greatest number of members possible = 5000 / 240 ≈ 20. Let the payment made by the single member be X. The rest 19 members paid TK. 240 each. So,  240×19 + X = 5000 or,  X = 5000 - 4560 = 440 TK

Explanation:

In 2000, the book value of a car was 2/3rd of the original purchase price, and in 2004, its book value was 1/2 of the original purchase price. By what percentage did the value of the car decrease from 2000 to 2004. Correct Answer 25% In 2000, the book value of a car was 2/3rd of the original purchase price, and in 2004, its book value was 1/2 of the original purchase price. By what percentage did the value of the car decrease from 2000 to 2004. Let the original price be P. Value in 2000 = 2P/3 Value in 2004 = P/2 So, percentage of decrease in value = (2P/3 - P/2) / (2P/3) x 100% = 25%

Explanation:

Per column inch (1 column * 1 inch) area newspaper advertisement costs Tk. 1,200. How much would a "5 columns by 3 inches" newspaper advertisement cost? Correct Answer Tk. 18,000 1 column x 1 inch ≡ 1200 TK So, total cost = 5 x 3 x 1200 = 18000 TK.

Explanation:

What is 35% of 11/56 of 160? Correct Answer 11 35% of 11/56 of 160= 35100×1156×160= 11

Explanation:

An empty pool is being filled with water at a constant rate, 3/5th of the pool has filled in 7 hours. How much more time will it take to completely fill the pool? Correct Answer 4 hours 40 minutes Remaining part = 1 - 3/5 = 2/5 3/5 part of the pool is filled in 7 hours So, 2/5 part of the pool is filled in 7 x (2/5) / (3/5) hours = 7 x 2 / 3 hours = 14 / 3 x 60 minutes = 280 minutes = 4 hours 40 minutes

Explanation:

How many countries have accepted 'Euro' as their common currency? Correct Answer 20 You can use the euro in 20 EU countries: Austria, Belgium, Croatia, Cyprus, Estonia, Finland, France, Germany, Greece, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Portugal, Slovakia, Slovenia and Spain.