In a bag, white mobile covers and black mobile covers are in the ratio of 4 : 7. If there are 280 black mobile covers, then how many white mobile covers are there in the bag?
Answer & explanation
Correct answer: option 3
Here,
White : Black
4 : 7
⇒ 7 units = 280
⇒ 1 unit = 40
⇒ No. of white balls = 4 x 40 = 160.