Question

Please answer q 7 8 9 10 11 12

Answer 1

now given

(7)

to find how many terms

tn=a+(n-1)d

111=3+(n-1)3

111=3+3n-3

111/3=n

n=37

so there are37 terms

(8) give n that two digit number that is divisible by 7

so first term is 7×2

so the difference is 7

now the last digit is 7×14

so the digits exactly divisible by7

are 13 terms

(9) a+(10-1)d=52.............(1)

a+(16-1)d=82................(2)

now (2)-(1)

a+15d-a-9d=82-52

6d=30

d=5

now from(1)

a+9(5)=52

a=52-45

a=7

so the 32 th term is

a+(32-1)d

=7+31(7)

=7+217

=224

(10) 124=a+(n-1)d

=4+(n-1)5

124=4+5n-5

124+1=5n

n=25

(11)

now given to find 184 th term

so

=3+(184-1)4

=3+(183)4

=735

(12)

5(a+4d)=8(a+(7)d)

5a+20d=8a+56d

-3a=36d

-a=12d

d=-a/12

now

13 th term is

(-12d+(13-1)-a/12)

a+12(-a/12)

a-a=0