A man spends Rs 1800 monthly on an average for the first four months and Rs 2000 monthly for the next eight months and saves Rs 5600 a year. His average monthly income is

Answer: C Expenses for first four months = 1800*4 = Rs 7200 Expenses for next eight months = 2000*8 = Rs 16,000 Saving = Rs 5600 Therefore, total annual income = Rs 28,800 Hence average monthly income = 28,800/12 = Rs 2400.

Q. No. 2:

A person covers half his journey by bus at 60 km/hr, half the remaining half by train at 30 km/hr and the rest by cycle at 10 km/hr. Find the average speed during the entire journey?

Answer: B Let the total distance travelled be x km Average speed = total distance / total time => x / {x/(2*60) + x/(4*30) + x/(4*10)} = 120/5 = 24 km/hr

Q. No. 3:

In a family of 8 males and few ladies, the average monthly consumption of grain per head is 10.8 kg. If the average monthly consumption per head be 15 kg in the case of males and 6 kg in the case of females, find the number of females in the family.

Answer: D Total consumption of males = 8*15 = 120 kg Total consumption of females = x*6 = 6x kg (where, x = number of females) Total average = (120+6x)/(8+x) = 10.8 => x=7.

Q. No. 4:

The average weight of 5 men is decreased by 3kg when one of them weighing 150kg is replaced by another person. This new person is again replaced by another person whose weight is 30 kg lower than the person he replaced. What is the overall change in the average due to this dual change?

Answer: A Total decrease in weight of 5 men = 3*5 =15 kg The weight of the new man = 150-15 = 135 kg The weight of the other man who replaces him = 135-30 = 105 kg Total weight reduction = 150-105 =45 kg. This is the total weight reduction of 5 men due to dual replacement. Hence average weight reduction = 45/5 = 9kg. Therefore average change = 9-6 = 3kg.

Q. No. 5:

There were 42 students in a hostel. Due to the admission of 13 new students, the expenses of mess increase by Rs 31 per day while average expenditure per head diminished by Rs 3. What was the original expenditure of the mess?

Answer: A Let the average expenditure per student be Rs x. Therefore, total expenditure of 42 students = 42x New total expenditure after inclusion of 13 students = (42x+13) New average expenditure = Rs (x-3) (42x+13)/(42+13) = (x-3) x = 196/13 Hence original expenditure = 196/13 * 42 = Rs 633.23

Q. No. 6:

The average of three numbers is 135. the largest number is 180 and the difference between the others is 25. The smallest number is