Math, asked by PranjalKumarDas, 1 year ago

How many two digit numbers are divisible by 3?

Answers

Answered by akashrishi
0
HI
HERE IS THE ANSWER
30

PranjalKumarDas: i need the long calculation
Answered by Anonymous
0

\huge{\underline{\underline{\bf{Solution:}}}}

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\tt Given \begin{cases} \sf{A.P \: : 12, 15, 18 ....... 99} \\ \sf{First \: term (a) = 12} \\ \sf{Common \: Difference(d) = 3} \\ \sf{Last \: term (A_n) = 99} \\ \sf{Number \: of \: terms (n) = ?} \end{cases}

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\Large{\underline{\underline{\bf{To \: Find :}}}}

We have to find number of terms (n).

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\Large{\underline{\underline{\bf{Explanation :}}}}

We know the formula to find the value of n.

\large{\star{\boxed{\sf{A_n = a + (n - 1)d}}}}

____________________[Put Values]

\sf{99 = 12 + (n - 1)3} \\ \\ \sf{\mapsto 99 = 12 + 3n - 3} \\ \\ \sf{\mapsto 99 = 9 + 3n} \\ \\ \sf{\mapsto 99 - 9 = 3n} \\ \\ \sf{\mapsto 90 = 3n} \\ \\ \sf{\mapsto \frac{\cancel{90}}{\cancel{3}} = n} \\ \\ \sf{\mapsto n = 30}

\large{\star{\boxed{\sf{n = 30}}}}

∴ Number of two digit numbers divisible by 3 is 30

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