Answer:
A.
1. 8/10 = 4/6
8 × 6 = 4 × 10
48 = 40 ✖️
2. 12/15 = 4/5
12 × 5 = 15 × 4
60 = 60 ✔️
B.
3. 18/n = 21/28
21n = 18 × 28
21n = 504
21n/21 = 504/21
n = 24
4. 12/16 = n/64
16n = 12 × 64
16n = 768
16n/16 = 768/16
n = 48
C.
5. correct answers : wrong answers
6:4
= 3:2
