28. The edges of a cube are all increased by 10%. What is the percentage increase in the
volume?

Percentage increase in volume will be

33.1

%

Step-by-step explanation:

Let the each edge of cube be

100

units.

Then its volume is

100

3

=

1000000

cubic units.

If each edge increases by

10

%

it becomes

110

units

and volume becomes

110

3

=

1331000

cubic units

Therefore increase in volume is

1331000

−

1000000

=

331000

cubic units

and percentage increase in volume is

331000

1000000

×

100

%

=

331

10

%

=

33.1

%

step-by-step explanation:

, and

for

step-by-step explanation:

we can analyze the pattern at which the terms increase. let us denote , , , so that we can call

note the following:

the pattern: to get the next term value, we just add the next term number (e.g. 1st, 2nd, to the previous term value (term values are the given numbers in the question, 1, 3, 6, 10, 15,

from , to get to , we add

from , to get to , we add

etc.

we need to form a recursive formula, a formula that has the next term as a function of the previous term. so a possible recursive formula can be

, and for