Answer:
20
Step-by-step explanation:
lets assume the number she thought of was x
[tex] \frac{x}{5} [/tex]
then she added 7 to it and got 11
[tex] \frac{x}{5} + 7 = 11[/tex]
l.c.m
[tex] \frac{x + 35}{5} = 11[/tex]
cross multiply
[tex]x + 35 = 11 \times 5[/tex]
[tex]x + 35 = 55 [/tex]
[tex]x = 55 - 35[/tex]
x = 20