how many 2 digit no.s are divisible by 3
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Answered by
3
First two digit number divisible by 3 = 12
Last two digit number divisible by 3 = 99
An arithmetic progression (A.P) is a progression in which the difference between two consecutive terms is constant.
A.P = 12,15,18,…,99
here
First term (a) = 12
Common difference (d) = 3
Let us consider there are n numbers then
an = 99
a + (n – 1)d = 99
a + (n – 1)d = 9912 + (n – 1)3 = 99
a + (n – 1)d = 9912 + (n – 1)3 = 9912 + 3n – 3 = 99
a + (n – 1)d = 9912 + (n – 1)3 = 9912 + 3n – 3 = 99n = 29+1
n = 30
∴ Two digit numbers divisible by 3 = 30.
Answered by
2
Answer:
30
Step-by-step explanation:
Here, 12,15,18,21 are in A.P
a = 12
d = 3
an = 99
an = a + (n-1)d # Formula for nth term of an A.P
99 = 12 + (n-1) 3
99 - 12 = (n-1) 3
87 / 3 = n-1
29 + 1 = n
∴ n = 30.
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