Question

if the cp of bananas be equal to the sp of 3 bananas, then
gain%is

Answer 1

Here, $C.P = 3$ × $S.P$

Sell price is 3 times less than the cost price. This suggests that the bananas were sold at a loss. So, the gain will be in minus.

We know, 
$S.P - C.P = Profit$

[∵ $C.P = 3S.P$]
$S.P - 3S.P = -2S.P$

Converting the gain to percentage yields...

$-2 * 100$%
 $=-200$% (ans.)