Question

The sum of three consecutive multiples of 7 is 420. Find these multiples.

Answer 1

Given :

• The sum of three consecutive multiples of 7 is 420.

To find :

• these multiples.

Solution :

⇒ Let's find the multiples of 7.

• 7 × 1 = 7
• 7 × 2 = 14

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⇒ Now, let's find the multiples.

→ x + (x + 7) + (x + 14) = 420

→ (x + x + x) + (7 + 14) = 420

→ (3x) + (21) = 420

→ 3x + 21 = 420

→ 3x = 420 - 21

→ 3x = 399

→ x = 399/3

→ x = 133

∴ x = 133

The consecutive multiples are :

⇒ x = 133

⇒ x + 1 = 133 + 1 = 134

⇒ x + 2 = 133 + 2 = 135