Question

What is the sum of 6 feet 10 inches and 8 feet 9 inches?

Answer 1

B. 15ft. 7in. 

Add the smaller measurement first, which in this case is inches. So you should have 19in. Then add feet, 14ft. Currently we have 14ft and 19in. But 19in can be simplified, since 12in is one foot. So take one foot out of 19 in and you have 7inches left. Add that one to 14. And in the end you should have 15ft and 7in. 

Answer 2

Lets first convert everything to inches.

6 feet= 12*6 = 72 + 10 = 82 inches
8 feet= 12*8 = 96+9 =  105 inches

Now add!

82+105 = 187

Now convert them back to feet.

187/12 = 15 feet

12*15 = 180

187 - 180 = 7 inches

15 feet. 7 inches. 

Final answer: B. 15 ft. 7 in.