Question 51 Problem Solving 2018 GMAT Quantitative Review

Question 51 Problem Solving 2018 GMAT Quantitative Review

Video explanation [PQID: PS01099]: Five machines at a certain factory operate at the same…

Comments

Thaosays

This is my solution:
Let the amount of products in the project is 100.
x: machine
4 machines make 100 products, so 1 machine will do 25 products (4x= 100)
Every in 4 machines needs the same 30 hours to make a product, the time to make a product will be 30 hours/25 products (30/25).
We also have 5 machine will do product so 1 machine will produce 20 products. Time to make 100 products with 5 machines is called “t”. Time to make a product with 5 machine will be t/20
Because the time to make a product is the same even with more machine, so: t/20= 30/25 => t= 24 (less than 30 hours as 6 hours).

Thao says

This is my solution:

Let the amount of products in the project is 100.

x: machine

4 machines make 100 products, so 1 machine will do 25 products (4x= 100)

Every in 4 machines needs the same 30 hours to make a product, the time to make a product will be 30 hours/25 products (30/25).

We also have 5 machine will do product so 1 machine will produce 20 products. Time to make 100 products with 5 machines is called “t”. Time to make a product with 5 machine will be t/20

Because the time to make a product is the same even with more machine, so: t/20= 30/25 => t= 24 (less than 30 hours as 6 hours).