please someone solve this

Answers
Question
In Amar's factory 216 machine parts are made in 3 days. Let's calculate how many machine parts will be made in 7 days.
Answer in Step-by-Step
Number of machine parts made in 3 days ⇒ 216
Number of machine parts made in 1 day ⇒
⇒ 72
Number of machine parts made in 7 days ⇒
⇒ 504
∴Amar's factory produces 504 machine parts in 7 days.
Additional Information
Unitary Method:
In this method, we find the value of one unit and using this value we find the values of the required numbers.
For example ⇒
The cost of 5 pens is 25. Find the cost of 9 such pens.
Answer:
Cost of 5 pens ⇒ 25
Cost of 1 pen ⇒ 25÷5 = 5
Cost of 9 pens ⇒ 5×9 =45
Let's try one more question.
Mia purchased 10 books for ₹150 and Manish purchased 7 books for ₹84. So who got the books at a cheaper cost?
Answer:
Amount Mia paid for 10 books ⇒ ₹150
Amount Mia paid for 1 book ⇒ 150÷10 = ₹15
Hence, Mia paid ₹15 for one book.
Amount Manish paid for 7 books ⇒ ₹84
Amount Manish paid for 1 book ⇒ 84÷7 = ₹12
Hence, Manish paid ₹12 for one book.
₹15 > ₹12
∴Manish bought the books for a cheaper cost.