Question

Sundram says. "I have thought of such a number, that if I multiply it by 4 and then
subtract 5. I get the same result as multiplying the number first by 2 and then adding 1,
What is the number that Sundram has thought of?
​

Answer 1

Consider the number Sundaram thought be 'a'.

Then, according to him,

4a-5=2a+1

➡️4a-2a=1+5

➡️2a=6

➡️a=6/2

➡️a=3

Therefore the number is 3.

Answer 2

$\large{\underline{\underline{\rm{Solution:}}}}$

$\rm{Sundaram\:thought\:of\:a\:number.}$

$\multimap\rm{Let\:the\:number\:be\:x.}$

$\rm{He\:multiplies\:it\:by\:4.}$

$\multimap\rm{Then,\:the\:number\:will\:be\:4x.}$

$\rm{Then,\:he\:subtracts\:it\:by\:5.}$

$\multimap\rm{Then,\:the\:number\:will\:be\:4x-5.}$

$\underline{\rm{Now,\:According\:to\:the\:Question:}}$

$\multimap\rm{4x-5 = (Number \times 2)+1}$

$\multimap\rm{4x-5 = (x \times 2)+1}$

$\multimap\rm{4x-5 = 2x+1}$

$\multimap\rm{4x-2x-5 = 1}$

$\multimap\rm{2x-5 = 1}$

$\multimap\rm{2x = 1+5}$

$\multimap\rm{2x = 6}$

$\multimap\rm{x = \dfrac{6}{2}}$

$\multimap\rm{x = 3}$

$\large{\underline{\underline{\rm{Final\:Answer:}}}}$

$\rm{The\:required\:number\:is\:3.}$