Question

A takes 9mins while B takes 12mins to make a candle. Working together how long will A and B take to make 7 candles?​

Answer 1

Given,

A takes 9 minutes to make a candle.

B takes 12 minutes to make a candle.

To find,

Together how much time they will take for making 35 candles.

Solution,

We can easily solve this mathematical problem by using the normal arithmetic method.

A can make,

In 9 minutes = 1 candle

In 1 minute = 1/9 candle

B can make,

In 12 minutes = 1 candle

In 1 minute = 1/12 candle

Together they can make,

In 1 minute = 1/9 + 1/12 = 4+3/36 = 7/36 candle

Or,

Together they can make,

7/36 candle in = 1 minute

1 candle in = 36/7 minutes

35 candles in = 36×35/7 = 180 minutes = 3 hours

Hence, together they can make 35 candles in 180 minutes or 3 hours.