4 mat-weaves can weaves 4 mats in 4 days.At the same rate,how many mats would be woven by 8 mat-weaves in 8 days ? Options:
A) 4
B) 8
C) 12
D) 16
E) 17

Rationale: solution let the required number of mats be x . more weaves , more mats ( direct proportion ) more days , more mats ( direct proportion ) ∴ 4 × 4 × x = 8 × 8 × 4 ⇔ x = ( 8 x 8 x 4 ) / ( 4 x 4 ) = 16 . answer d
Answer: D