How are you with logic and sql queries?

Question

MySQL

Guys, I'm scratching my head, I need your help.
The situation is.
There are 2 tables 'product' and 'info';
In product - description of the product, price (prices are different), ...
In info - id (product), information about the product, date of purchase.
You need to find out the profit for a certain date or period of time.
Here's what I came up with...
You need to calculate the number of products, from info, purchased on a specific date, find out the price by their ID from the product table, multiply the price by the number of a certain product, and summarize these products ..
But later I decided to add a field with a price in info, now info has a price for 1 item, BUT by making a query
(SELECT SUM(price) FROM `info` WHERE info.buyer != '0' AND info.day = '10-02-2018'
) output i get thisprntscr.com/ickyhi
What can you advise how to implement it correctly so that only 60 would be obtained in the end?