Q. 12+13+14+15+16+17+18+19+20+21 = ? :: Arithmetic Progression (A.P.) / Consecutive Numbers

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Arithmetic Progression (A.P.) / Consecutive Numbers

Q. 12+13+14+15+16+17+18+19+20+21 = ?

Solⁿ

Add 4 to the 1^st no: 12 + 4 = 16, Put 5 at the end of 16 → 165

Ans: 165

Tricks: "Add 4 to the 1^st number, then write 5 after it."

Following the Tricks :

Q. 36+37+38+39+40+41+42+43+44+45 = ?

Solⁿ

Add 4 to the 1^st no: 36 + 4 = 40, Put 5 at the end of 40 → 405

Ans: 405

Trick: i. "Add 4 to the 1^st number, ii. Write 5 at the end."

Q. 85+86+87+88+89+90+91+92+93+94 = ?

Solⁿ

85 + 4 = 89

Put 5 at the end of 16 → 895

Ans: 895

Trick: i. "Add 4 to the 1^st number, ii. Write 5 at the end."