Answer:
There area 14 one cent stamps
Step-by-step explanation:
Let
x -----> the number of 1 cent stamps
y -----> the number of 8 cent stamps
z -----> the number of 12 cent stamps
we know that
0.01x+0.08y+0.12z=1.78 -------> equation A
x=y+4 ------> y=x-4 -----> equation B
x=2z -----> z=0.5x ------> equation C
substitute equation B and equation C in equation A and solve for x
0.01x+0.08(x-4)+0.12(0.5x)=1.78
0.01x+0.08x-0.32+0.06x=1.78
0.15x=1.78 +0.32
0.15x=2.10
x=14
therefore
There area 14 one cent stamps
Answer:
c
Step-by-step explanation:
a. 3in, 4in, 5 in
5^2 ? 3^2 + 4^
25 ? 9 + 16
25 = 25
Because the two sides are equal, this is a right triangle.
b. 5in, 6in, 7in
7^2 ? 5^2 + 6^2
49 ? 25 + 36
49 < 61
Because 49 < 61, this is an acute triangle.
c. 8in, 9in, 12in
12^2 ? 8^2 + 9^2
144 ? 64 + 81
144 < 145
Because 144< 145, this is an acute triangle.
Answer:
56 problems
Step-by-step explanation:
So we already know that the answer is: 56. However, a good help is knowing how to obtain this answer from the data provided.
Tony's quiz had 80 questions
Tony correctly answered 70% of them.
We can always write a percentage amount as a ratio by dividing the amount by 100.
.
This means that for every 100 questions, tony will respond correctly 70.
So, if Toni did a questionnaire of n questions, the amount that will answer correctly is calculated by the following expression:
If 
then:
