Question

when 40% of a number is added to 42 the result is the number itself then find the number

Answer 1

40x/100 +42 =x
4x/10 +42 =x
42 = 10x -4x/10
420=6x
x =70

Answer 2

Answer:

Required number = n = 70

Explanation:

Let a number be n

40% of the number = 40% of n

According to the problem given,

40% of a number is added to 42 the result is the number itself

40% of n + 42 = n

40% × n + 42 = n

$\frac{40}{100}\times n+42 = n$

$\implies \frac{2}{5} \times n+42 = n$

$\implies 42 = n - \frac{2n}{5}$

$\implies 42 = \frac{5n-2n}{5}$

$\implies 42\times 5= 3n$

$\implies \frac{210}{3}=n$

$\implies 70=n$

Therefore,

Required number = n = 70

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