Question

Find the correct result, remember that the math is exact.

$$\begin{gathered} 1+4=5 \\ 2+5=12 \\ 3+6=21 \\ 5+8=\_\_\_ \end{gathered}$$

Answer 1

Find the pattern in the given expressions

Given,

$$\begin{gathered} 1+4=5 \\ 2+5=12 \\ 3+6=21 \\ 5+8=\_\_\_ \end{gathered}$$

By observing them we can see that pattern

$$\begin{gathered} 1+4\times 1=5 \\ 2+5\times 2=12 \\ 3+6\times 3=21 \end{gathered}$$

So, the pattern followed is,

$a+b\times a=\mathrm{result}$

where $a$ is the first operand and $b$ is the second operand.

By following the pattern, $5+8=\_\_$ is $5+8\times 5=45$

Hence the correct result is $45$.