ARITHMETIC

PROGRESSIONS

• Identifying whether the given

situation / statement forms an A.P.

3. The cost of digging a well after every meter of digging, when it costs Rs.150 for the first meter and rises by Rs.50 for each subsequent meter.

Sol:

Cost for digging each subsequent meters are:

150,

200,

250,…

Since the difference between consecutive terms is constant, given sequence

is an A.P.

2) In which of the following situations, does the list of numbers

involved make an A.P. and why?

+1m

+Rs.50

1m

Rs.150

Exercise 5.1 1(iii)

Since the difference between consecutive terms is not constant, the given

list of numbers is not an A.P.

4. The amount of money in the account every year, when Rs.10000 is

deposited at compound interest at 8% per annum.

Sol:

Amount of money in the account for successive years:

10000,

10800,

11664, …

2) In which of the following situations, does the list of numbers

involved make an A.P. and why?

Rs.10000

Principle

+

8% of Rs.10000

Interest

=

Rs.10800

Amount

Rs.10800

Principle

+

8% of Rs.10800

Interest

=

Rs.11664

Amount

Exercise 5.1 1(iv)