0.52 X 2.1 =
Help i don’t understand

Students are given 3 minutes for each multiple-choice question and 5 minutes for each free-response question on a test. there are 15 questions on the test, and students are given 51 minutes to take it.how many multiple-choice questions are on the test?

What is another way to express 36 +32

If mary had 320 toy cars and she gave her friend 50 cars and then she gave her brother 72 more cars how much toy cars would mary have left ● explain with proper details