2/7.
2/7 + 5/7 =1 Just add the numerator if the denominator is the same
Answer:
$0.90
Step-by-step explanation:

3 dozen = 36

0.4 × y = 36 × 0.1
0.4y = 3.6
0.4y ÷ 0.4 = 3.6 ÷ 0.4
y = 9
The best thing to do is to find the cost of one sweet, and to do this, divide 42 by 7.
42/7= 6
Therefore, one sweet costs 6p.
To find the cost of 8 sweets, you've got to multiply 6 by 8, and this gives you 54p.
Therefore, 8 sweets cost 54p
This is basically just finding unit rate and multiplying.
<span>Hope this helps :)</span>