Question

If the common difference of an A.P. is 3 , then find the value of a20-a16
a) 5
b) 3
c) 15
d) 20
e) option 5
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Answer 1

Answer:

the correct answer of this question will be 12 but however the 12 is not given in any option so I don't prefer any options

Answer 2

Answer:

12

Step-by-step explanation:

a20 = a + (20 - 1)3

∴ a20 = a +  57

a16 = a + (16 - 1)3

∴ a16 = a + 45

∴ a20 - a16 = 12