can u help me in 7th grade math hw?

Question

two different prime numbers, each less than 100, are multipled.
the answer ends in 2.
what numbers could it be?
(find the 5 possible answers.)

Answer 1

Why don't you first look at all the prime numbers less than 100 (there aren't that many), and then you can tackle this problem?

The primes less than 100 are as follows {note: 1 is NOT a prime!}:

2 - 3 - 5 - 7 - 11 - 13 - 17 - 19 - 23 - 29 - 31 - 37 - 41 - 43 - 47 - 53 - 59 - 61 - 67 - 71 - 73 - 79 - 83 - 87 - 89 - 97

Then you just need to look at the last digits in each prime to see if it would multiply to a number ending in 2 when multiplied by another prime. So let's look at 2 first. 2 multiplied by any number ending in 1 will result in a number ending in 2, so right away we can see by looking at our list that the following would fit the answer:

2 x 11
2 x 31
2 x 41
2 x 61
2 x 71

So there's your 5 answers!

Answer 2

First, find the primes < 100

1, 2, 3, 5, 7, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67,
71, 73, 79, 83, 89, 97

From this list we see that only possible final digits are:

1, 2, 3, 5, 7, 9

so that there are only 36 possible combinations.

For every odd number, a, and odd number , b,

a* b = c, where c is an odd number.

Since 2 is not an odd number, the only combination must include the 2. The only combinations that fit are primes that end in 2 and 1.
From our list above we see that

End in 1
-----------
1
31
41
61
71

End in 2
-----------
2

Answer 3

1 and 2

Answer 4

11 and 2

31 and 2

41 and 2

61 and 2

71 and 2

Am i correct?