If the cost of 4 pens and 6 note books is ₹800, then find the cost of 6 pens and 9 note books.
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → ₹1200
The second set, 6 pens and 9 notebooks, is the first set taken one and a half times (4 × 1.5 = 6 and 6 × 1.5 = 9), so its cost is one and a half times as much. The separate prices are not needed.
Cost of 4 pens and 6 notebooks \(=800\)
Cost of 6 pens and 9 notebooks \(\displaystyle =\frac{3}{2}\times800=1200\)