1.
Solution.
Let x be amount of bananas in the packet,
x/2 be amount of bananas, phiwe had after she shared with her cousin,
(x/2)/2 = x/4 be amount of bananas, phiwe had after she shared with her brother.
we receive:
x/4 = 3
x = 3 * 4
x = 12
Answer: 12
2.
Solution.
Let x be amount of metres of the damage material,
y be amount of metres of the normal material.
From the conditions of the question we will receive the system of two equations:
x + y = 12 (1)
7x + 8y = 98.50 (2)
from equation (1) we receive:
y = 12 - x.
Now substitute y into equation (2):
7x + 8*(12 - x) = 98.5
7x + 96 - 8x = 98.50
-x = 98.5 - 96
-x = 2.5
x = -2.5
From conditions of the question we get Phuzma bought (-2.5) metres of the damage material. This statement is meaningless, that means there is a mistake in this question.
Answer: she bought -2.5 metres of the damaged material
3.
Solution.
"Between them the pay R6,00" means a difference between how much did Nancy pays and her sister.
Let x be the price per metre of ribbbons, Nancy buys, then
2x is the price per metre of ribbons, her sister buys.
From the condition of the question we will receive an equation:
15*x - 6*2x = 6
15x - 12x = 6
3x = 6
x = 6/3
x = 2
2x = 2 * 2 = 4
Then R2.00 is the price per metre of ribbons, Nancy buys,
R4.00 is the price per metre of ribbons, her sister buys.
Answer: R2.00 is the price per metre of ribbons, Nancy buys,
R4.00 is the price per metre of ribbons, her sister buys.
4.
Solution.
Let x be the amount of shirts at R4,00,
y be the amount of shirts at R4,50.
From the condition of the question we will receive a system of two equations:
x + y = 10 (1)
4*x + 4.5 *y = 43.5 (2)
from equation (1) we receive:
y = 10 - x
Now substitute y into equation (2):
4x + 4.5*(10 - x) = 43.5
4x + 45 - 4.5x = 43.5
-0.5x = 43.5 - 45
-0.5x = -1.5
x = -1.5/(-0.5)
x = 3,
then y =10 - x = 10 - 3 = 7
Answer: I bought 3 shirts at R4,00 and 7 shirts at R4,50.