10 students of Elena's classmates like to make jewellery.
<u>Step-by-step explanation:</u>
Let total no.of classmates who liked the jewellery = x
Here, in the given problem, given she asked her classmates '20'. So, it clearly shows that total number of students/classmates = 20. Also, in that, 50% said like to make jewellery. Now find 'x' as below,



Hence, the total number of classmates who liked to make Jewellery = 10
The second one should be the answer
For matrix subtraction, you subtract the corresponding cell of the second matrix from the first. So, looking at the first spot, you have 4 (from the first matrix) - 4 (from the second matrix) = 0 (the first number in the output matrix). Continuing that for the next spot, -4 - -3 = -4 + 3 = -1. Finally, -2 - 5 = -7. This means your answer is [0 -1 -7].
The problem is:

We now do L.C.M. of numerator and add, also do L.C.M. of denominator and add together:

Dividing by a fraction is same as multiplying by its reciprocal, so we have:

x cancels out, so can multiply and write:

This is the simplified form.
ANSWER: 
Answer:
A
Step-by-step explanation:
Volume varies directly with the square of the radius, so:
V = k r²
When V = 80, r = 4.
80 = k (4)²
k = 5
V = 5r²
When r = 3:
V = 5 (3)²
V = 45
The flow is 45 L/min.