Okay. There are 18 girls in the school choir. The ratio of girls and boys is 1:2. With this being the case, there are double the amount of boys as girls. 18 * 2 is 36. There are 36 boys in the school choir.
If the ratio of girls to boys is 1 to 2, that means that there are twice as many boys as girls. So to find this, you simply multiply the number of girls by 2. With this, your answer is 36 boys. Hope this helps
