Question

the result of a number when increase by 15 % is 161.find this number

Answer 1

Let's assume the number to be X
Now, the questions says that 15% of X, when added to X = 161
This basically means that 115% of X = 161.
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So... 115/100 x 'X'.= 161
         115X = 16100
         X= 16100/115
         X= 140
That is, your answer.Hope it helps.

Answer 2

$\text{Assume the number to be } x.\\ \text{Then } (1+0.15)\times x=161.\\ x = 161 / 1.15 = 140.$