Question

What is the sum of the numbers that are both multiples of 7 and factors of 42​

Answer 1

42 is a composite number. 42 = 1 x 42, 2 x 21, 3 x 14, or 6 x 7. Factors of 42: 1, 2, 3, 6, 7, 14, 21, 42. Prime factorization: 42 = 2 x 3 x 7.

When 42 is a clue in the FIND THE FACTORS puzzles always use 6 and 7 as the factors.

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Math and Science with My Kids shared a topological puzzle. It was interesting to read of his child’s frustration and eventual triumph. I learned something reading these, and you can

Answer 2

Given:

Numbers that are multiples of 7 and factors of 42​

To find:

The sum of such numbers

Solution:

The sum of the numbers that are multiples of 7 and factors of 42​ is 84.

We can find the sum by following the given process-

We know that the sum can be obtained by first determining the numbers that are multiples of 7 as well as the factors of 42.

So, we will first identify the numbers that are multiples of 7 and factors of 42.

The number 42 can be obtained as follows-

1×42, 2×21, 3×14, 6×7

So, the factors of 42= 1, 2, 3, 6, 7, 14, 21, 42

Now, the multiples of 7 are 7, 14, 21, 28, 35, 42 and so on.

The numbers common are 7, 14, 21, and 42.

The sum can be obtained by adding these common numbers.

The sum of the numbers that are both multiples of 7 and factors of 42​=(7+14+21+42)

=84

Therefore, the sum of the numbers that are multiples of 7 and factors of 42​ is 84.