Scholarship Exam Preparation App
Class 6 - (Intelligence Test )
Comprehension - Numbers
Choose the correct number to replace the question mark: 7, 15, 31, 63, 127, ?
a :
245
b :
254
c :
255
d :
260
Explanation :
Each forward number is (backward number × 2) + 1. (7 × 2) + 1 = 15;
(15 × 2) + 1 = 31;
(31 × 2) + 1 = 63;
(63 × 2) + 1 = 127.
Therefore, (127 × 2) + 1 = 254 + 1 = 255.
(15 × 2) + 1 = 31;
(31 × 2) + 1 = 63;
(63 × 2) + 1 = 127.
Therefore, (127 × 2) + 1 = 254 + 1 = 255.