Question

The average rainfall in a city for the first four days was recorded to be 0.40 inch. The rainfall on the last two days was in the ratio of 4 : 3. The average of six days was 0.50 inch. What was the rainfall on the fifth day?

(a) 0.60 inch

(b) 0.70 inch

(c) 0.80 inch

(d) 0.90 inch

Answer 1

Correct option (c) 0.80 inch

Explanation:

The average rainfall in six days = 0.5 inch.

Hence, total rainfall in six days = 0.5 × 6 = 3 inch

The average rainfall in a city for the first four days = 0.4 inch

So, total rainfall in these four days = 0.4 × 4 = 1.6 inch

Hence, rainfall in the last two days = 3 – 1.6 = 1.4 inch

Now, it’* given that the rainfall on the last two days was in the ratio of 4:3. Hence, rainfall on the fifth day

= 1.4 × [4/(4 + 3)] = 1.4 × (4/7) = 0.8 inch