Question

235 people are at a summer camp. There are 35 more boys than girls, and 70 fewer adults than girls. How many people of each group are at the camp?

Answer 1

There are 90 girls, 125 boys, and 20 adults.

Explanation:

Let x be the number of girls. How many boys were there?

x + 35

How many adults were there?

x - 70

We know that 235 people are at RSM summer camp. Use this to make an equation.

x + (x + 35) + (x - 70) = 235

x + x + 35 + x - 70 = 235

3x - 35 = 235

3x - 35 + 35 = 235 + 35

3x = 270

3x ÷ 3 = 270 ÷ 3

x = 90

x, x + 35, x - 70

90, 125, 20

Answer 2

125 boys, 90 girls and 20 adults

Explanation:

Let the number of boys be x

Let the number of girls be y

Let the number of adults be z

If there are 235 people at the summer camp, then;

x + y+ z = 235 ..... 1

If there are 35 more boys than girls, then;

x = y + 35 .... 2

If there are 70 fewer adults than girls then;

y = z - 70

z = y - 70....3

Substitute 2 and 3 into 1;

x + y+ z = 235 ..

(y+35)+y+(y-70) =235

3y -35 = 235

3y = 270

3y/3 = 270/3

y = 90

Since x = y + 35

x = 90 + 35

x = 125

Also z = y - 70

z = 90+70

z = 20

There are 125 boys, 90 girls and 20 adults