If 2d = 5c, then all of the following are true except
a. 2/5=c/d
b. 5/2=d/c
c. 2/c=5/d
d. 2/d=5/c

Option d is correct

Step-by-step explanation:

Given that:

Option d.

By cross multiply we have;

 which is true.

Option b.

By cross multiply we have;

 which is true.

Option c.

By cross multiply we have;

 which is true.

Option d.

By cross multiply we have;

2c = 5d

which is not true.

Therefore, all of the following are true except

the answer is 510

step-by-step explanation:

15 • 13 = 195

15 • 12 = 180

15 • 5 = 75

12 • 5 = 60

195 + 180 = 375

375 + 75 = 450

450 + 60 = 510

well there are two answers for that.

1: you need 120 ones then that will equal up to 120.

2: you could also do one 100 and 2 tens.

those are the answers that i have thought of.