Top answers

Smartphones are on sale. A smartphone now costs only 80% of its original price. By how many per cent would we need to increase the current price of the smartphone in order to bring it back to the original price?

Let a be the original price, b - the current price, and x - the answer we are looking for, so we need to increase b by x % in order to get a . So a=b+b x% (the original price a equals the current price b + t...
AP
Answered by Aleksejs P. • Maths tutor
3971 Views

In a sale the price of a shirt is reduced by 60%. The sale price is £7.98. What is the original price?

Reduced by 60%=4/5 Original price * 0.4=£7.98 Original price=7.98/0.4=19.95 ∴ Original price= £19.95
RR
Answered by Riccardo R. • Maths tutor
7572 Views

Kelly is trying to work out the two values of w for which 3w-w^3=2. Her values are 1 and -1. Are her values correct?

Sub in her values to see if the LHS and the RHS of the equation equate: w=1: 3(1)-(1)^3=2 >>> 3-1=2 >>> 2=2 ✅ Therefore 1 is a correct value. w=-1: 3(-1)-(-1)^3=2 >>> -3+1=2 >&g...
EB
Answered by Emma B. • Maths tutor
5442 Views

The mass of a substance is increasing exponentially. Initially its mass is 37.5g, 5 months later its mass is 52g. What is its mass 9 months after the initial value to 2 d.p?

M=37.5e kt 52=37.5e k 5 52/37.5=e 5k ln(52/37.5)=5k (1/5) (ln(52/37.5))=k k≈0.06538 when t=9, M=37.5e 9*0.06538 M=67.54
RR
Answered by Riccardo R. • Maths tutor
4759 Views

At a school number of boys : number of girls = 9 : 7 There are 116 more boys than girls. Work out the total number of students at the school.

B:G --> 9:7 Expressed as fractions of the whole group, boys are 9/16 of the group and girls are 7/16 of the group. We can use algebra to work out the total group number. For our working, I will use x to r...
DM
Answered by Dionne M. • Maths tutor
16639 Views