Question

riddle
i am a number
tell my identity
take me seven times over
and add a fifty
reach triple century
you still need forty

Answer 1

the number is 140 because if the number is 'x' then,

x+70+50+40= 300

∴x + 160 = 300

∴x = 300 - 160

∴ x = 140

Answer 2

Let the number be n.

According to the question,  

7n + 50 + 40 = 300

⇒7n + 90 = 300

⇒7n = 300 − 90

⇒7n = 210

⇒ n = 7/210

⇒ n = 30

Thus, the required number is 30.