Question

141. The number of observations in a survey
is 40. If the mean of the first 10
observations is 4.5 and that of
remaining is 3.5, then the mean of the
whole survey is
(1) 2-82
(2) 3.80
(3) 3.75
(4) 4.25
142. A right circular cylinder of maximum
volume is cut from a solid cube of
edge 14 cm. The total surface of the
cylinder is
(1) 924 cm
2.
(2) 1134 cm
2.
(3) 2464 cm
(4 616cm2​

Answer 1

Answer:

(3), (1)

Step-by-step explanation:

141. sum=4.5x10+3.5x30=45+105=150

mean: 150/40=3.75

142. radius=7, height=14

plug it into the formula.

A=2πr^2+2πrh

A≈923.63