2023 · Q99
Question: What is the cost of 15 pens, 21 pencils and 18 note books?
Statement IThe cost of 7 pens, 6 pencils and 5 note books is Rs. 200.
Statement IIThe cost of 3 pens, 8 pencils and 7 note books is Rs. 210. Mark option (a) if the question can be answered by using one of the statements alone, but cannot be answered using the other statement alone. Mark option (b) if the question can be answered by using either statement alone. Mark option (c) if the question can be answered by using both the statements together, but cannot be answered using either statement alone. Mark option (d) if the question cannot be answered even by using both the statements together.
Elementary MathematicsAlgebra
- AThe question can be answered by using one of the statements alone, but cannot be answered using the other statement alone
- BThe question can be answered by using either statement alone
- CThe question can be answered by using both the statements together, but cannot be answered using either statement alone
- DThe question cannot be answered even by using both the statements together
Explanation
15x+21y+18z=l(7x+6y+5z)+m(3x+8y+7z): 7l+3m=15, 6l+8m=21, 5l+7m=18 gives l=m=3/2; value=(3/2)(200+210)=615. Option (c).