The chief by 3 3/4 kg of apple's 7 1/4 kilograms of peers and 10 1/8 kilograms with orange about how many kilograms of fruit did the chief by all together

(3 3/4) + (7 1/4) + (10 1/8)

Change the mixed numbers to fractions:

(15/4) + (29/4) + (81/8)

Write all of the fractions with a common denominator (8):

(30/8) + (58/8) + (81/8)

Add the fractions:

(30 + 58 + 81) / 8  =  169/8

Change the sum back to a mixed number:

169/8 = 21 and 1/8 kg.

the answer is the first electromagnet (a). this is because it has more coils around the ferromagnetic material. increasing the number of coils increases the surface area in which the metal interacts with the current in the coil. this enables more atoms in the metal to become aligned hence becoming more magnetized.