If 53 * 13 = 33, 39 * 13 = 26 and 74 * 26 = 50, then what will be 37 * 21 = ?

Correct option is A

Given:

53 * 13 = 33

39 * 13 = 26

74 * 26 = 50

37 * 21 = ?

Logic: $$\frac{1st + 2nd}{2} = 3rd$$​​
​$$\frac{(53+13)}{2} = \frac{66}{2}=33$$​​

​$$\frac{(39+13)}{2} = \frac {52}{2} = 26$$​​

​$$\frac{(74+26)}{2} = \frac{100}{2} =50$$​​

Similarly,

​$$\frac{(37+21)}{2} = \frac{58}{2}=29$$

Correct answer is (a).