Smartphone or tablet plus phone?

Question

Iron

Due to the fact that the smartphone of the current LG optimus one has become buggy, and flashing does not help solve the problem. Decided to go for a replacement.
But here I stumbled upon the question that is in the title. Those. there is a budget of 10-11 thousand.
There are such sketches of options
1) Nokia Lumia 520
2) Lenovo IdeaTab A3000 16Gb 3G and Nokia 301.
Interested in both the opinion of these options and your own decisions.
Key tasks: internet infrequent (search for answers to a question), calls quite often (salesperson), navigation, whatsapp.

Answer 1

take 720 instead of 520 (720 fits into the budget, if you believe the liaison, you can read about the difference here, for example www.3dnews.ru/653315 )
IMHO, carrying a tablet with you for the sake of a rare Internet and navigation is troublesome and strange
for Nokla, navigation is pretty standard not bad

Answer 2

Nexus 7 (you can use the previous one to save money) + the simplest phone with the minimum necessary set of functions.
Calls are important to you - you won’t look back at the battery, the tablet will sit down - to hell with it. And the tablet is much more convenient to work with, especially if there is something to carry it in (although 7 inches fits well into a jeans / jacket / jacket pocket).
Just buy a cover for the nexus.