Please help me l don’t understand

Question

asked Nov 2, 2023 222k views

1 Answer

Quat · Answer 1 · 2023-11-07T23:32:10+0000

a. Let
be the number of daytime calls Eshwa makes, and
the number of evening calls. Then the cost
(in pence) of making
d+e calls is

$C = \boxed{50d + 40e}$

b. £1 = 100p, so the cost
(in £) is 1/100 of the cost found in part (a),

$C' = (50d + 40e)/(100) = \boxed{\frac d2 + \frac{2e}5}$

c. If Eshwa makes 30 of each type of call in a month, then the total cost (in £) is

$C' = \frac{30}2 + \frac{2\cdot30}5 = \boxed{27}$

c2. If Eshwa makes 20 daytime calls and 50 evening calls, then the total cost (in £) is

$C' = \frac{20}2 + \frac{2\cdot50}5 = \boxed{30}$

d. Let
e=40 and
C'=42 . Solve for
.

$42 = \frac d2 + \frac{2\cdot40}5$

$42 = \frac d2 + 16$

$\frac d2 = 26$

$d = \boxed{52}$