Question

In the summer of 2012, in New Delhi, the mean temperature of Monday to
Wednesday was 41°C and of Tuesday to Thursday was 43 Cc . If the temperature
on Thursday was 15% higher than that of Monday, then the temperature in cC
on Thursday was
(A) 40 (B) 43
(C) 46 (D) 49

Answer 1

Answer:

(c) 46

Explanation:

We are given that:

1- The mean temperature of Monday to Wednesday was 41 degrees

This means that:

$\frac{Monday+Tuesday+Wednesday}{3} = 41$

This can be rewritten as:

Monday + Tuesday + Wednesday = 3*41 = 123

Therefore:

Tuesday + Wednesday = 123 - Monday ...............> equation I

2- The mean temperature of Tuesday to Thursday was 43 degrees

This means that:

$\frac{Tuesday+Wednesday+Thursday}{3} = 43$

This can be rewritten as:

Tuesday + Wednesday + Thursday = 3*43 = 129 .....> equation II

3- The temperature on Thursday was 15% higher than the temperature on Monday

This means that:

Thursday = 15%Monday+Monday = 1.15Monday ....> equation III

Substitute with equation III in equation II:

Tuesday + Wednesday + 1.15Monday = 129 ..........> equation IV

Substitute with equation I in equation IV as follows:

123 - Monday + 1.15Monday = 129

0.15Monday = 129 - 123 = 6

Monday = 40

Now, substitute with the value of Monday in equation III to get the value of Thursday as follows:

Thursday = 1.15Monday = 1.15 * 40 = 46 degrees celcius

Hope this helps :)

Answer 2

Answer:

The temperature on Thursday was 46Cc.

Step-by-step explanation:

• Let the temperature on Monday,Tuesday and Wednesday be x,y,z respectively.
• Average Temperature of Monday,Tuesday and Wednesday is 41Cc.

Hence we can write:

x+y+z = 41×3=123 .............(i)

• Temperature on Thursday was 15% more than Monday, i.e. x+15x/100 = 115x/100
• Average temperature of Tuesday,Wednesday and Thursday was 43 Cc.

Hence we can write:

y+z+115x/100 = 43×3 =129.............(ii)

(ii) - (i) can give 115x/100 - x = 6

or, 15x/100 = 6

or, x= 600/15

So the temperature of Thursday is 115x/100 = (115/100)×(600/15) = 46 Cc