Answer:
25.55
Step-by-step explanation:
Let us take the number he thinked of be x .
On doubling it :-
→ N = 2x
On adding 19 :-
→ N = 2x + 19
According to Question :-
→ 2x + 19 = 70.1
→ 2x = 70.1 - 19
→ 2x = 51.1
→ x = 51.1/2
→ x = 25.55
Hence the required answer is 25.55
