Question
A teacher marked a certain average number of papers per
day for the first 30 days. In the next 10 days, she marked 90 papers daily. This increased her overall average by 5 papers per day. What was the average for the first 30 days?Solution
Let, average number of papers marked in first 30 days is x So, (30 × x + 10 × 90)/40 = x + 5 Or, 30x + 900 = 40x + 200 Or, 10x = 700 Or, x = 70
Inactive Nitrogen and Argon gases are usually used in electric bulbs in order to
Zero group was introduced by
Which part of the brain is responsible for balance and coordination?
Before X-ray examination (coloured X-ray) of the stomach, patients are given suitable salt of barium becauseÂ
Which of the following is/are correct?
1. Displacement current can exist in vacuum
2. Magnetic field can exist without electric f...
Lamberts law is related to –
The main thinking part of the brain is:
Study the given information.
Consider the force on a current carrying straight conductor in a magnetic field.
(i) It is perpendicular...
Marbles come under which category of rockes?
Which of the following part of the earth doesn’t allow the S wave to pass through itself?