Consider the following pattern :
115²=11*(11+1) hundred + 25 =13225
Using hte above pattern , find the squares of
(1) 125 (2) 325 (3) 85

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Solution

Hi!

Here is the answer to your question.

Given, 115² = 11 × (11 + 1) hundred + 25 = 13225

The square of any number ending in 5 can be calculated using the relation,
(a5)² = a (a + 1) hundred + 25

125²= 12 × (12 + 1) hundred + 25 = 12 × 13 × 100 + 25 = 15600 + 25 = 15625

325² = 32 × (32 + 1) hundred + 25 = 32 × 33 × 100 + 25 = 105600 + 25 = 105625

85² = 8 × (8 + 1) hundred + 25 = 8 × 9 × 100 + 25 = 7200 + 25 = 7225

Cheers!

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Similar questions

91 \times 11 \times 8

91 \times 11 \times 1 = 1001

91 \times 11 \times 2 = 2002

91 \times 11 \times 3 = 3003

30 = 2^{1} \times 3^{1} \times 5^{1}

(1 + 1) (1 + 1) (1 + 1) = 2 \times 2 \times 2 = 8

30

8

1, 2, 3, 5, 6, 10, 15, 30

1 = \frac{1}{2} \{1 \times (1 + 1)\} 1 + 2 = \frac{1}{2} \{2 \times (2 + 1)\} 1 + 2 + 3 = \frac{1}{2} \{3 \times (3 + 1)\} 1 + 2 + 3 + 4 = \frac{1}{2} \{4 \times (4 + 1)\}

While using the pattern used to square numbers with unit digit 5 for 105, we get: (___ x 11)hundreds + 25. Fill in the blank with the correct value.

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