Pyano dersi

Admin Ptsi Eyl. 22, 2008 9:07 am

Number & Math Play

Piano Lessons
Ayla, Belma, Ceyda, and Damla all began piano lessons last year. Ceyda took twice as many lessons as Belma. Ayla took 4 lessons more than Damla but 3 fewer than Ceyda. Damla took 15 lessons altogether.
How many lessons did Belma take?

Ayla , Belma, Ceyda, Damla geçen sene hep birlikte piyano dersi almaya başladılar. Not aldığım deftere baktığımda şunlar gördüm. Ceyda Belma'nın iki katı ders almış.Ayla Damla'dan dört ders fazla almış ama Ceyda'dan 3 ders daha az almış.
Ceyda toplam 15 ders aldığına göre Belma kaç ders almıştır?

Belma took 11 lessons.
Let A stand for Ayla, B for Belma, and so on. C = 2B A = D + 4 = C - 3 D = 15

Since D = 15, you know that A = 19. You also know that C - 3 = 19, which means that C = 22. And since C = 2B, 22 = 2B, which means that B = 11.