CAT Exam

FIND SUM OF SERIES
1+2^2/7+3^2/7^2+4^2/7^3+5^2/7^4+ ....UPTO INFINITY

Read Solution (Total 1)

shortcut:
s = (1+x)/(1-x)^3

here take x as 1/7.
and 49/27

conventional method is a bit lengthy. if anybdy needs it will post.
10 years agoHelpfull: Yes(0) No(0)

CAT Other Question

A ship 156 km away from the shore springs a leak which admits 7/3 tons of water in 6.5 min. A pump throws out water at the rate of 15 tons in 1 hour. If 68 tons of water can sink the ship, find the lowest average speed just enough to reach the shore.

(a) 20 kmph
(b) 15 kmph
(c) 10 kmph
(d) 25 kmph A square is drawn by joining the midpoints of the sides of a given square. A third square is drawn inside the second square in the same way and this process is continued indefinitely. If a side of the first square is 8 cm, the sum of the areas of all the squares such formed (in sq.cm.)is

(a) 128

(b) 120

(c) 96

(d).None of these