Ni hua is an adventurous traveler. he skydives twice in every island he visits and skydives thrice in every peninsula he visits. in the last decade, ni hua went skydiving a total of 45 times in the 19 islands and peninsulas that he visited.

Solution:

Let Ni Hua visited x  island and y peninsulas.

we are given that

Ni Hua went skydiving a total of 45 times in the 19 islands and peninsulas that he visited.

So we can write

Now solve these two equations togethere using substitution  as below:

So we can write

Hence Let Ni Hua visited 7  island and 12 peninsulas.