Question
The average marks of all the students decreased by 2
when it was found that marks of one of the student were wrongly interpreted as 80 instead of 40. Find the total number of students.Solution
Let number of students be 'N' and sum of marks of all the students be 'S'. ATQ: We have, [(S - 80 + 40) /N] = (S/N) - 2 Or, (S/N) - [(S - 40) /N] = 2 Or, (40/N) = 2 So, 'N' = (40/2) = 20 Therefore, total number of students are 20.
58     69      56       ?      54       73
...In what ratio coffee at 325 Rs/kg should be mixed with the coffee at 375 Rs/kg so that after mixture its rate become 340 Rs/kg if the quantity of 1st ty...
There are three mixtures A, B and C. Mixture A contains 11% of water and B contains 16% of water. If A and B are mixed together than resultant mixture c...
In a zoo, there are rabbits and pigeons. If heads are counted, there are 200 and if legs are counted, there are 580.How many pigeons are there.
A petrol pump has a blend of 40 liters of petrol and diesel in the ratio of 5:3. After selling 16 liters of the mixture, 12 liters of petrol are added t...
9 litre of milk is taken out from a container and replaced by water. This process is repeated once more, the ratio of quantity in container (M: W) is 16...
In a jug, there is a mixture of apple and orange juice in the ratio of p:3. When 10 liters of Apple are added, the ratio of Apple to orange juice become...
The seller sold a total of 40 kg of rice bags, comprising Basmati Rice and Brown Rice. The cost price of Basmati rice is Rs.72/kg, and that of Brown ric...
Ajay lists an item at 42% higher than its cost price and gives a 20% discount on this marked price. Determine the percentage of p...
Anju deposited two parts of a sum of Rs. 30,000 in different banks at the rate of 15% per annum and 12% per annum respectively. In one year she got Rs. ...
Relevant for Exams:
