Question
The average number of books read by 40 Indian students
in a year is 30. If the books read by their librarian are included, the average increases by 2 books. Find the number of books read by the librarian.Solution
ATQ, Total books read by the students excluding librarian = 40 × 30 = 1200 Let the books read by the librarian be ‘b’. According to the question, (1200 + b) / (40 + 1) = 30 + 2 1200 + b = 41 × 32 1200 + b = 1312 b = 1312 – 1200 b = 112. So, the librarian read 112 books.
If (8x - 3y) = 196 and 7x:4y = 35:16, then find the value of (x² + 4y²).
48 24 24 48 ? 1536
...If 9 : 12 :: 12: x, and 28: 42:: 42: y, then the value of 2x + y is:Â
If y + 1/y = 2 then find y117 + 1/(y117)
If x −y =4and xy =45,thenthevalueof x 3 −y3is:
- If [4a - (1/2a)] = 6, then find the value of [16a² + (1/4a²) - 8]
If the 14th term of an arithmetic series is 6 and 6th term is 14, then what is the 95th term?

(288 ÷ 8)² × (144 ÷ 24)³ = 24 × ? × (51840 ÷ 20)