Power of Focus for students by Sandeep Maheshwari

Principal Focus

Sandeep has a wooden study table. He wants to measure the height of the table. Which of the following tools can be used by Sandeep to measure the height of his study table?

A student focussed the leaf epidermal peel under the low power of microscope but could not see all the parts. He should:

The focus of the parabola

Vaibhav can do a piece of work in 60 days. He works there for 15 days and then Sandeep alone finishes the remaining work in 30 days. In how many days will Vaibhav and Sandeep working together finish the work?