Solving Zone

QUESTION

There were 50 students in a class. Due to the admission of 10 new students, the expenses of mess were increased by 80 Rs per day while the average expenditure per head diminished by 2 Rs. What was the original expenditure of the mess?
1. Rs. 8060
2. Rs. 2060
3. Rs. 1080
4. Rs. 1000

SOLUTION

Let the average expenditure per head before admission of new students was X Rs.
Total expenses before joining new students = 50 X
Total expenses after joining new students =60 × (X - 2)
∴ 60 (X - 2) -50 X = 80
Or, 10 X = 200
Or, X = 20
Hence the original expenditure of the mess was 20 × 50 = 1000 Rs

QUESTION

The average marks scored by Abhishek in English, Science, Mathematics and Hindi is less than 15 from that scored by him in English, Hindi, Geography and Mathematics. What is the difference of marks in Science and Geography scored by him?
1. 30
2. 50
3. 60
4. Data inadequate
5. None of these

SOLUTION

3
(E+H+G+M)/4 - (E+S+M+H)/4 = 15
⇒ G – S = 60