Question

The smallest number when increased by ` ` 1 ` ` is exactly divisible by 12 , 18 , 24 , 32 and 40 is

Answer 1

the number will be exactly divisible by 12,18,24,32,40 when 1 is added to it
so it will be LCM of these -1
12=2²×3
18=2×3²
24=2³×3
32=2^5
40=2³×5
LCM =2^5×3²×5
=1440
so number is 1439