F.1 English's maths

a)
let the wight of tea be x g.
(1-40%-25%)x = 560
x=1600
therefore there is 1600g of mixed tea.

b)
weight of tea A= 1600 * 40%=640g
weight of tea B= 1600 * 25%=400g

c) total cost= 0.64*15 + 0.4*18 +0.56*20 = $28

1.
(a) Let x be the weight of that can of mixed tea.
560g =(1 -40% -20%)x
560g = 0.4x
x =560g /0.4
x =1400g
so the weight of that can of mixed tea is 1400g.

(b)The weight of that can of A in that can of mixed tea =1400g *40%
=560g
The weight of that can of B in that can of mixed tea =1400g *25%
=350g

(c)The cost of that can of A in that can of mixed tea =$15 /(1kg *1000g) *560g
=$8.4
The cost of that can of B in that can of mixed tea =$18 /(1kg *1000g) *350g
=$6.3
The cost of that can of C in that can of mixed tea =$20 /(1kg *1000g) *560g
=$11.2
The cost of that can of mixed tea =$8.4 +$6,3 +$11.2
=$25.9

1a. Let x be a can of mixed tea.
The percent of C type of tea:
=100%-40%-25%
=35%
The weight of a can of mixed tea:
35%x=560
x=560/35%
x=1600g
Therefore the weight of a can of mixed tea is 1600g.

1b. The weight of A:
=1600*40%
=640g
The weight of B:
=1600*25%
=400g

1c. The cost of that can of mixed tea:
=15*(640/1000)+18*(400/1000)+20*(560/1000)
=15*0.64+18*0.4+20*0.56
=9.6+7.2+11.2
=28
Therefore the cost of that can of mixed tea is $28.