Question

Price of 15 maths book is $825 and the price of 19 science book is $855. Jack buys 3 maths book and 2 science book, how much he has to pay?​

Answer 1

Given that:

• The price of 15 maths book is $825.
• And the price of 19 science book is $855.
• Jack buys 3 maths book and 2 science book.

To Find:

• How much he has to pay?

Let us assume:

• The price of one maths book be x.
• And the price of one science book be y.

According to the question.

↠ 15x = 825

↠ x = 825/15

↠ x = 55

And,

↠ 19y = 855

↠ y = 855/19

↠ y = 45

Finding the total cost:

Cost 3 maths book + Cost of 2 Science book

= 3x + 2y

= 3(55) + 2(45)

= 165 + 90

= 255

Hence,

• He has to pay $255.

Answer 2

$\huge\bold\red{Given :-}$

• The price of 15 maths book = ₹ 825
• The price of 19 science book = ₹ 855
• Jack buys 3 maths book and 2 science books

To Find :-

• How much money he has to pay ?

Let us assume :-

• Let the price of 1 math book = X
• Let the price of 1 science book = Y

$\small\bold\blue{According \: to \: the \: question : }$

Cost of one math book -

• 15X = ₹825
• X = ₹ 825 ÷ 15
• X = ₹ 55

Cost of one science book -

• 19Y = ₹ 855
• Y = ₹ 855 ÷ 19
• Y = ₹ 45

Total cost Jay have to pay -

• = 3X + 2Y
• = (3 × ₹55 ) + ( 2 × ₹45)
• = ₹165 + ₹ 90
• = ₹255

Hence,

• He had to pay ₹255