//Pratik Dayama - PRIMPAL
#include <iostream>
using namespace std;
#define MOD 1000000007
 
//prime[k] is number of primes with k+1 digits
//should be precomputed separately or taken from the internet
int prime[9] = {4, 25, 168, 1229, 9592, 78498, 664579, 5761455, 50847534};
 
//calculate 10^exp using exponentiation by squaring
long long pow10(long long exp) {
    long long ans = 1, base = 10;
    while(exp > 0) {
        if(exp & 1)
            ans = (ans*base) % MOD;
        base = (base*base) % MOD;
        exp >>= 1;
    }
    return ans % MOD;
}
 
int main() {
    int t;
    long long n, k;
    cin >> t;
    while(t--) {
        cin >> n >> k;
        if(n == k+1) //we know there are 9 palindromes of length 1
            cout << 9 * prime[k-1] << '\n';
        else //there are 9 * 10^((x-1)/2) palindromes of length x
            cout << (9 * prime[k-1] * pow10((n-k-1)/2)) % MOD << '\n';
    }
    return 0;
}

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2
2 1
4 2