Question

find the 31st term of an AP whose 11th term is 38 and the 16th term is 73.
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Answer 1

Step-by-step explanation:

a11=a+10d=38 (1)

a16=a+15d=73 (2)

subtracting equation 2 from 1

a+10d-(a+15d)=38-73

a+10d-a-15d=-35

-5d=-35

d=35/5

d=7

a+10(7)=38

a+70=38

a=38-70=-32

now a31=a+30d

=-32+30(7)

=-32+210

=178

31st term is 178 ans.