Answer:
Let x be odd such that LCM {x,40} = 1400 .
Since 1400 = 23×52×7 , then
x ∈ {5m×7n∣(m,n) ∈ {0,1,2}×{0,1}} .
By testing these values, we find that x = 175 .
The answer for this is 10
If a number equals the same number, there are infinite solutions
Example: 5=5, which is true, so there are infinite solutions
If a number equals a different number, there are no solutions
Example: 5=2, which isn’t true
The first option and the third option are correct.
(Although, it's probably way too late now...)
The answer I would go with is A.
