Home
Class 10
MATHS
What is the common difference of an A P....

What is the common difference of an A P. in which `a_21-a_7=84`

Text Solution

Verified by Experts

Let the first term of A.P. be 'a' and common difference be 'd'.
since, `a_(21)-a_(7)=84`
`:. (a+20d)-(a+6d)=84`
`rArr 14d=84 rArr d=6`
Hence, the common difference is 6.
Promotional Banner

Topper's Solved these Questions

  • ARITHMETIC PROGRESSION

    NAGEEN PRAKASHAN|Exercise Problem From NCERT/exemplar|20 Videos

  • ARITHMETIC PROGRESSION

    NAGEEN PRAKASHAN|Exercise Exercise 5a|5 Videos

  • AREA RELATED TO CIRCLES

    NAGEEN PRAKASHAN|Exercise Revision Exercise Long Answer Question|6 Videos

  • CIRCLES

    NAGEEN PRAKASHAN|Exercise Revision Exercise Long Answer Questions|3 Videos

Similar Questions

Explore conceptually related problems

What is the common difference of an A.P. in which a_(21) - a_(7) = 82 ?

What is the common difference of an AP in which a_(27) -a_(7) = 80?

What is the common difference of an AP in which a_(18)-a_(14)=32 ?

What is the common difference of an AP in which a_(18)-a_(14) = 32?

What is the common difference of an A.P. is 2 in which a_(11) - a_(7) ?

What is the common difference of an A.P. - 5 , - (4)/(3), (7)/(3) , 6 , …. ?

If the common difference of the A.P.in which T_(7)=9 and T_(1)T_(2)T_(7) is least,is' d' then 20d is -

What is the common difference of the following A.P. series? 7,19,31,43,……

Write the common difference of an A.P.whose nth term is a_(n)=3n+7.