A number and the number formed by reversing its digits are both two-digit whole numbers. For example, 23 reversed is 32, and 23 + 32 = 55, which is a multiple of 11. For how many two-digit numbers (with no zero digit) is the sum of the number and its reverse equal to 55?

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4. A two-digit number 10a + b plus its reverse 10b + a equals 11(a + b). For this to be 55 we need a + b = 5 with a, b from 1 to 9. The pairs are (1,4),(2,3),(3,2),(4,1), giving 14, 23, 32, 41 — that is 4 numbers.

A number and the number formed by reversing its digits are both two-digit whole numbers.
For example, 23 reversed is 32, and 23 + 32 = 55, which is a multiple of 11.
For how many two-digit numbers (with no zero digit) is the sum of the number and its reverse equal to 55?

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More Class 6 Properties of Whole Numbers practice

A number and the number formed by reversing its digits are both two-digit whole numbers.For example, 23 reversed is 32, and 23 + 32 = 55, which is a multiple of 11.For how many two-digit numbers (with no zero digit) is the sum of the number and its reverse equal to 55?

Step-by-Step Solution

Master this chapter in 30 minutes a day.

More Class 6 Properties of Whole Numbers practice

A number and the number formed by reversing its digits are both two-digit whole numbers.
For example, 23 reversed is 32, and 23 + 32 = 55, which is a multiple of 11.
For how many two-digit numbers (with no zero digit) is the sum of the number and its reverse equal to 55?