Question

If $60*3=36$ and $11*7=81$, then what is the value of $5*13$?
A. 65
B. 66
C. 81
D. 51

Answer 1

Hint : We have to treat the given problem in the form of general intelligence and try to find the actual condition for the given operation $*$. We use the same the same operation for $5*13$ and find the final solution.

Complete step-by-step answer :
The given problem is more like a general intelligence problem rather than a mathematics problem.
The given operation is not direct multiplication, rather an operation defined in a particular way.
We have to carefully understand the condition for the operation to find the solution for $5*13$.
The first given part is $60*3=36$. We know the change of digits for 36 will give us 63 and that can be got from the addition of two given numbers 60 and 3.
Similarly, we can see the addition of 11 and 7 in $11*7=81$ gives 18 and we interchange the digits to get 81.
So, the condition for the operation $*$ is to add the numbers and then interchange the digits.
We have $5*13$. The addition of 5 and 13 gives $5+13=18$.
The interchange of digits gives 81. The correct option is C.
So, the correct answer is “OPTION C”.

Note : We can’t use the normal form of multiplication for the operation $*$. The condition is different for the numbers. It can only be determined by the given solutions to assume.