How to simplify 4 to 1 ratio

How much dextrose 70% must be mixed with dextrose 5% to prepare 1,000 ml of dextrose 20%?

In the sixth grade 13 out of 20 students have a dog if there are 152 sixth grade students how many of them have a dog

Acaterer charges $500 plus $30 per guest to cater a wedding. walt and traci don't want to spend more than $8000 on catering. write and solve an inequality in terms of the number of guests, g, that can be invited. a) 30g ? 8000; g ? 267 b) 500g < 8000; g < 16 c) 500 + 30g < 8000; g < 250 d) 500 + 30g ? 8000; g ? 250