# Time and Work

- Time and work problems can be solved using unitary method.
- More persons will do more work in same time.
- More persons will take less time to do the same work.
- Remuneration is based on the amount of work done, which
is in direct proportion to
*speed of work*. If three persons can separately do a job in 3, 4, 5 days respectively, then remuneration will be divided in ratio 1/3 : 1/4 : 1/5.

## Exercise

- Ramdin can reap a field in 30 days. What part of the field would he have reaped in 25 days?
- If 12 men working 8 hours a day can construct a shed in 5 days, then in how many days will 8 men working 10 hours a day complete the same job?
- Three ants separately can gobble a dead grasshopper in 3, 4 and 6 days respectively. How many days will they take together to finish off the poor chap? If the grasshopper weighs 63 grams, find the share of each.
- If a chicken and a half lays an egg and a half in a day and a half, how long does it take to get a dozen eggs from a chicken?
- A dozen pens cost 15 rupees. How much would a hundred pens cost?
- 400 grams cake costs 80 rupees. How much would a 1.5 kg cake cost?
- It rained 80 mm in first 20 days of April. What would be the total rainfall in April?
- 50 grams of fish food is sufficient for 8 fish for a day. How much would 12 fish require in a day?
- 50 grams of fish food is sufficient for 8 fish for a day. On the same amount of food, for how many days can 2 fish survive?
- A man builds a chair in 4 days, working 6 hours a day. How many hours should he work in a day if he wants to do it in 3 days instead of 4 days?
- Four men working together take 3 hours to paint a wall. How much time would 6 men take to do the same job?
- A man earns Rs 18000 in 3 months.

(a) How much time would he take to earn Rs 30000?

(b) How much will he earn in 7 months? - Ram can build a table in 6 days while Shyam requires 8 days for the same work. Working together,

(a) how many days would they require to construct 7 tables?

(b) how many tables can they construct in 48 days? - A man and a woman working together can sow a field in 20/9 days. The man alone can do it in 4 days. How much time would the woman working alone take to sow the field?

## Answers

**1.**5/6th

**2.**6 days

**3.**days; 28 grams, 21 grams, 14 grams

**4.**18 days

**5.**Rs 125

**6.**Rs 300

**7.**can not say

**8.**75 grams

**9.**4 days

**10.**8 hours per day

**11.**2 hours

**12.**(a) 5 months (b) Rs 42000

**13.**(a) 24 days (b) 14 tables

**14.**5 days