Aparent is buying two types of chocolate truffles for the children. the oldest child likes white chocolate (w), the younger two like dark chocolate (d) and the spouse likes white chocolate (w). three white chocolate truffles (w) cost the same as two dark chocolate truffles (d). if the parent bought 5 white chocolate truffles(w) and 10 dark chocolate truffles (d), and spent $60.00, how much was each dark chocolate truffle?

The price of single dark chocolate truffle was $4.5.

Step-by-step explanation:

Let the price of white chocolate be x and dark chocolate be y.

Three white chocolate truffles cost the same as two dark chocolate truffles. Mathematically can be written as:

...[1]

Number of white chocolate truffles = 5

Cost of 5 white chocolate truffles = 5x

Number of dark chocolate truffles = 10

Cost of 10 dark chocolate truffles = 10y

Total money spend on  5 white chocolate truffles and 10 dark chocolate truffles= $60.00

..[2]

Solving [1] ans [2] ,we get :

x = $3

y = $4.5

The price of single dark chocolate truffle was $4.5.

a_n = a_1 + (n - 1)d

the first term is 6.

the common difference d = ?

when you find d, replace n with 7 and d with the common difference to find your answer.