Need help ASAP with this ratios question. I really don’t get it?

Question

The ratio of boys to girls in a group is 7:1. If there are 54 more boys than girls, work out how many boys there are.

Answer 1

Let

B = the number of boys

G = the number of girls

The ratio of boys to girls is 7:1. Therefore

B/G = 7/1 = 7

Multiply each side of this equation by G to obtain

(B/G)*G = 7*G

That is,

B = 7G (1)

There are 54 more boys than girls. Therefore

B = G + 54 (2)

Substitute equation (1) into (2).

7G = G + 54

Subtract G from each side.

7G - G = G + 54 - G

6G = 54

Divide each side by 6.

(6G)/6 = 54/6

G = 9

From (1), obtain

B = 7G =7*9 = 63

Answer:

B = 63

G = 9

Check the answer.

B/G = 63/9 = 7 (correct)

G + 54 = 9 + 54 = 63 (correct)