10. There are 39 boys and 23 girls in a dance group. Every week, 6 boys and 8 girls join the group and no one leaves the group. What is the total number of people in the dance group in the week when the number of boys is equal to the number of girls?
A 144
B 154
C 164
D 174
E 184
10. D Initially there are $(39-23)=16$ more boys than girls in the group. Each week $(8-6)=2$ more girls than boys join the group. Therefore it will take $16 \div 2=8$ weeks for the number of girls to equal the number of boys. Hence the total number of people in the group when this occurs is $2 \times(39+8 \times 6)=2 \times 87=174$.