A) 2
B) 3
C) 4
D) 5
Correct Answer: B
Solution :
Let the number of books and notebooks be a and b respectively. We have, \[4a+5b=32\] ?(i) and \[5a+4b=31\] ?(ii) On multiplying Eq. (i) by 4 and Eq. (iii) by 5 and then subtracting, we get \[\begin{align} & \,\,16a+20b=128 \\ & \underline{\begin{align} & \,\,25a+20b=155 \\ & \,-\,\,\,\,\,\,\,-\,\,\,\,\,\,\,\,\,\,\,- \\ \end{align}} \\ & \,\,\,\,\,\,\,\,\,\,\,-9a=-27 \\ \end{align}\] \[a=3\]You need to login to perform this action.
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