Answer:
62
Step-by-step explanation:
well, we start by expressing the number:
a b
we understand that using the above expression, the value of the number is 10a + b
using the information in the question,
a = 3b (1)
and,
11b + 11a = 88 (2) (derived using 10a + b form)
hence, when substituting (1) into (2):
11b + 33b = 88
44b = 88
b = 2 (3)
sub (3) into (1)
a = 6
hence, the number is 62
Answer:
7.5 L of 10% solution and 22.5 L of 30% solution
Step-by-step explanation:
Volume of 10% solution plus volume of 30% solution = total volume of 25% volume.
x + y = 30
Acid in 10% solution plus acid in 30% solution = total acid in 25% solution.
0.10 x + 0.30 y = 30 × 0.25
0.10 x + 0.30 y = 7.5
Solve the system of equations, using either substitution or elimination. I'll use substitution:
x = 30 − y
0.10 (30 − y) + 0.30 y = 7.5
3 − 0.10 y + 0.30 y = 7.5
0.20 y = 4.5
y = 22.5
x = 30 − y
x = 7.5
Sarah needs 7.5 L of 10% solution and 22.5 L of 30% solution.
Answer: 92
Step-by-step explanation: Subtract 257 & 162 to get your answer :)
