The ratio of the $11^{th}$ term to the $18^{th}$ term of an AP is $2 : 3 .$ Find the ratio of the $5^{th}$ term to the $21^{st}$ term and also the ratio of the sum of the first five terms to the sum of the first $21$ terms.

Important Questions on Arithmetic Progressions

HARD

10th CBSE

IMPORTANT

NCERT EXEMPLAR PROBLEMS-SOLUTIONS MATHEMATICS>Chapter 5 - Arithmetic Progressions>Exercise>Q 7

Show that the sum of an AP whose first term is

a

, the second term

b

and the last term

c

, is equal to

\frac{(a + c) (b + c - 2 a)}{2 (b - a)} .

HARD

10th CBSE

IMPORTANT

NCERT EXEMPLAR PROBLEMS-SOLUTIONS MATHEMATICS>Chapter 5 - Arithmetic Progressions>Exercise>Q 8

Solve the equation

- 4 + (- 1) + 2 + . .. + x = 437 .

HARD

10th CBSE

IMPORTANT

NCERT EXEMPLAR PROBLEMS-SOLUTIONS MATHEMATICS>Chapter 5 - Arithmetic Progressions>Exercise>Q 9

Jaspal Singh repays his total loan of

Rs . 118000

by paying every month starting with the first instalment of

Rs . 1000

. If he increases the instalment by

Rs . 100

every month, what amount will be paid by him in the

30 th

instalment? What amount of loan does he still have to pay after the

30 th

instalment?

HARD

10th CBSE

IMPORTANT

NCERT EXEMPLAR PROBLEMS-SOLUTIONS MATHEMATICS>Chapter 5 - Arithmetic Progressions>Exercise>Q 10

The students of a school decided to beautify the school on the annual day by fixing colourful flags on the straight passage of the school. They have $27$ flags to be fixed at intervals of every $2 m$ . The flags are stored at the position of the middle most flag.

Ruchi was given the responsibility of placing the flags. Ruchi kept her books where the flags were stored. She could carry only one flag at time. How much distance she did cover in completing this job and returning back to collect her books? What is the maximum distance she travelled carrying a flag?