The cost of one pencil, two pens and four erasers is ₹ 22 while the cost of five pencils, four pens and two erasers is ₹ 32. How much will three pencils, three pens and three erasers cost?
(a)₹ 21
(b)₹ 24
(c)₹ 27
(d)₹ 30
Answer
Answer (as printed): C
Explanation
Let the cost of 1 pencil, 1 pen and 1 eraser be $₹ x, ₹ y$ and $₹ z$ respectively. Then, $x+2 y+4 z=22$ and $5 x+4 y+2 z=32$ Adding (i) and (ii), we get: $6(x+y+z)=54$ or $x+y+z=9$. ∴ Cost of 3 pencils, 3 pens and 3 erasers $$=3(x+y+z)=₹(3 \times 9)=₹ 27 .$$
Explanation as extracted from the printed page; notation may be imperfect.