Cost of 2 apples, 3 bananas and one coconut is $\text{ ₹ }26$. Also the cost of 3 apples, 2 bananas and two coconuts is $\text{ ₹ }35$. Then the cost of 12 apples, 13 bananas and 7 coconuts is

Let number of apples, bananas and coconut be x, y and z respectively

$$\begin{gathered} 2x+3y+z=26 ......\left(1\right) \\ 3x+2y+2z=35.....\left(2\right) \end{gathered}$$

Multiplying Eq (l) with 3 and eq (ii) with 2 and then add both the equations

$\begin{array}{l}6x+9y+3z=78\\ \frac{6x+4y+4z=70}{12x+13y+7z=148}\end{array}$

So, Cost of 12 apples, 13 bananas and 7 coconuts is $\text{ ₹ }148$.