App Logo

No.1 PSC Learning App

1M+ Downloads
If thirty observation have an average of 20 and 20 observations have a mean of 30 then what is the average of all observations?

A25

B60

C50

D24

Answer:

D. 24


Related Questions:

In levelling, the correction for curvature in metres is equal to
T. Square is used for drawing
Which bond comprises of one course of a header to three or five courses of stretchers
A point. is 3 cm above HP and 2 cm behind VP. Which of the following statements is true
An RCC column of 30 cm diameter is reinforced with 6 bars 12 mm dia. placed symmetrically along the circumference. It carries a load of 40000 kg axially, the stress developed is