Question

A little bug ate 135 tiny flies in 5 days.Each day, it ate 10 more flies than it did on previous day. How many small flies had the bug eaten?
a)after three days =
b)after four days=

Answer 1

Let bug ate x flies on day 1

Bug will eat flies on day 2 = x + 10

On day 3 = x + 20

On day 4 = x + 30

On day 5 = x + 40

Total,

x + x + 10 + x + 20 + x + 30 + x + 40 = 135

5x + 100 = 135

5x = 35

x = 35/5 = 7

So after 3 days he will eat, flies on 4th day and 5th day together

or, x + 30 + x + 40 = 7 + 7 + 30 + 40 = 85 flies

after 4 days he will eat, flies eaten on 5th day only

or, x + 40 = 7 + 40 = 47 flies

Answer 2

Answer:

Let the number be_n

n+(n+10×1)+(n+10×2)+(n+10×3)+(n+10×4)=135

5n+100=135

n=35/5=7 n=7

(a)After 3 days- n+(n+10×1)+(n+10×2)

3n+30

3n= 7×3=21

21+30=51

After 3 days the bug had eaten 51 tiny flies.

(b) After four days- n+(n+10×1)+(n+10×2)+(n+10×3)

4n+60

4n=4×7=28

28+60=88

After four days the bug had eaten 88 tiny flies.....Hope this will help you