One girl can eat 112 chocolates in half a minute, and her boy friend can eat half as many in twice the length of time. How many chocolates can both boy and girl eat in 12 seconds ?

Girl eats 112 chocolates in 30 sec

so she can eat in 12 sec is 12 x 112/30 = 44.8 chocolates.

Her boy friend can eat one-half of 112 in twice of 30 sec

so he can eat 56 in 60 sec

Then he can eat in 12 sec is 56 x 12/60 = 11.2 chocolates.

Hence, together they can eat = 44.8 + 11.2 =56 chocolates in 12 seconds.